[470] This value is much smaller than that got by Wundt as above. No

reason for the difference is suggested by Mr. Cattell. Wundt calls

attention to the fact that the figures found by him give an average,

0.720'', exactly equal to the _time interval_ which in his experiments

(_vide infra_, chapter on Time) was reproduced without error either

way, and to that required, according to the Webers, for the legs to

swing in rapid locomotion. "It is not improbable," he adds, "that

this psychic constant, of the mean association-time and of the most

correct appreciation of a time-interval, may have been developed under

the influence of the most usual bodily movements, which also have

determined the manner in which we tend to subdivide rhythmically longer

periods of time." (Physiol. Psych., ii, 286). The _rapprochement_

is of that tentative sort which it is no harm for psychologists to

make, provided they recollect how very fictitious and incomparable

mutually all these averages derived from different observers, working

under different conditions, are. Mr. Cattell's figure throws Wundt's

ingenious parallel entirely out of line.--The only measurements of

association-time which so far seem likely to have much theoretic

importance are a few made on insane patients by Von Tschisch (Mendel's

Neurologisches Centralblatt, 15 Mai, 1885, 3 Jhrg., p. 217). The

simple reaction time was found about normal in three patients, one

with progressive paralysis, one with inveterate mania of persecution,

one recovering from ordinary mania. In the convalescent maniac and

the paralytic, however, the association-time was hardly half as much

as Wundt's normal figure (0.28'' and 0.23'' instead of 0.7'--smaller

also than Cattell's), whilst in the sufferer from delusions of

persecution and hallucinations it was twice as great as normal (1.39''

instead of 0.7''). This latter patient's time was sixfold that of the

paralytic. Herr von Tschisch remarks on the connection of the short

times with diminished power for clear and consistent processes of

thought, and on that of the long times with the persistent fixation

of the attention upon monotonous objects (delusions). Miss Marie

Walitzky (Revue Philosophique, xxviii, 583) has carried Von Tschisch's

observations still farther, making 18,000 measurements in all. She

found association-time increased in paralytic dementia and diminished

inmania. Choice time, on the contrary, is increased in mania.

[471] Mind, xii, 67-74.

[472] Compare Bain's law of Association by Contiguity: "Actions,

Sensations, and States of Feeling, occurring together or in close

succession, tend to grow together, or cohere, in such a way that, when

any one of them is afterwards presented to the mind, the others are

apt to be brought up in idea" (Senses and Intellect, p. 327). Compare

also Hartley's formulation: "Any sensations A, B, C, etc., by being

associated with one another a sufficient Number of Times, get such a

power over the corresponding Ideas _a, b, c,_ etc., that anyone of the

sensations A, when impressed alone, shall be able to excite in the Mind

_b, c,_ etc., the ideas of the rest." (Observations on Man, part i,

chap. i, § 2, Prop. x.) The statement in the text differs from these

in holding fast to the objective point of view. It is _things_, and

objective _properties in things_, which are associated in our thought.

[473] Encyclopædia Britannica, 9th Ed., article Psychology, p. 60. col.

2.

[474] Physiol. Psych., 2d ed. ii, 300.

[475] The difficulty here as with habit _überhaupt_ is in seeing

how new paths come _first_ to be formed (cf. above, p. 109).

Experience shows that a new path _is_ formed between centres for

sensible impressions whenever these vibrate together or in rapid

succession. A child sees a certain bottle and hears it called 'milk,'

and thenceforward thinks the name when he again sees the bottle.

But why the successive or simultaneous excitement of two centres

independently stimulated from without, one by sight and the other

by hearing, _should_ result in a path between them, one does not

immediately see. We can only make hypotheses. Any hypothesis of the

specific mode of their formation which tallies well with the observed

facts of association will be in so far forth credible, in spite

of possible obscurity. Herr Münsterberg thinks (Beiträge zur exp.

Psychologie, Heft i, p. 132) that between centres excited successively

from without no path ought to be formed, and that consequently all

contiguous association is between _simultaneous_ experiences. Mr. Ward

(_loc. cit._) thinks, on the contrary, that it can only be between

_successive_ experiences: "The association of objects simultaneously

presented can be resolved into an association of objects successively

attended to.... It seems hardly possible to mention a case in which

attention to the associated objects could not have been successive. In

fact, an aggregate of objects on which attention could be focussed at

once would be already associated." Between these extreme possibilities,

I have refrained from deciding in the text, and have described

contiguous association as holding between both successively and

coexistently presented objects. The physiological question as to how

we may conceive the paths to originate had better be postponed till it

comes to us again in the chapter on the Will, where we can treat it in

a broader way. It is enough here to have called attention to it as a

serious problem.

[476] Essay, bk. ii, chap. xxxiii, § 6. Compare Hume, who, like Locke,

only uses the principle to account for unreasonable and obstructive

mental associations:

"'Twould have been easy to have made an imaginary dissection of the

brain, and have shown why, upon our conception of any idea, the animal

spirits run into all the contiguous traces, and rouse up the other

ideas that are related to it. But though I have neglected any advantage

which I might have drawn from this topic in explaining the relations of

ideas, I am afraid I must here have recourse to it, in order to account

for the mistakes that arise from these relations. I shall therefore

observe, that as the mind is endowed with a power of exciting any idea

it pleases; whenever it dispatches the spirits into that region of the

brain in which the idea is placed, these spirits always excite the

idea, when they run precisely into the proper traces, and rummage that

cell which belongs to the idea. But as their motion is seldom direct,

and naturally turns a little to the one side or the other: for this

reason the animal spirits, falling into the contiguous traces, present

other related ideas in lieu of that which the mind desired at first

to survey. This change we are not always sensible of; but continuing

still the same train of thought, make use of the related idea which is

presented to us, and employ it in our reasoning, as if it were the same

with what we demanded. This is the cause of many mistakes and sophisms

in philosophy; as will naturally be imagined, and as it would be easy

to show, if there was occasion."

[477] _Op. cit._ prop. xi.

[478] See Chapter III, pp. 82-5.

[479] I strongly advise the student to read his Senses and Intellect,

pp. 544-556.

[480] Time and Space, p. 266. Compare Coleridge: "The true practical

general law of association is this: that whatever makes certain parts

of a total impression more vivid or distinct than the rest will

determine the mind to recall these, in preference to others equally

linked together by the common condition of contemporaeity or of

_contiguity_. But the will itself, by confining and intensifying the

attention, may arbitrarily give vividness or distinctness to any object

whatsoever." (Biographia Litteraria, Chap. v.)

[481] Leviathan, pt. i, chap. iii, _init._

[482] I refer to a recency of a few hours. Mr. Galton found that

experiences from boyhood and youth were more likely to be suggested by

words seen at random than experiences of later years. See his highly

interesting account of experiments in his Inquiries into Human Faculty,

pp. 191-203.

[483] For other instances see Wahle, in Vierteljsch. f. Wiss. Phil.,

ix, 144-417 (1885).

[484] I retain the title of association by similarity in order not to

depart from common usage. The reader will observe, however, that my

nomenclature is not based on the same principle throughout. Impartial

redintegration connotes neural processes; similarity is an objective

relation perceived by the mind; ordinary or mixed association is a

merely denotative word. _Total recall, partial recall,_ and _focalized

recall,_ of associates, would be better terms. But as the _denotation_

of the latter word is almost identical with that of association by

similarity, I think it better to sacrifice propriety to popularity, and

to keep the latter well-worn phrase.

[485] No one has described this process better than Hobbes: "Sometimes

a man seeks what he hath lost; and from that place and time wherein

he misses it, his mind runs back from place to place and time to time

to and where and when he had it; that is to say, to find some certain

and limited time and place, in which to begin a method of seeking.

Again, from thence his thoughts run over the same places and times to

find what action or other occasion might make him lose it. This we

call _Remembrance_, or calling to mind. Sometimes a man knows a place

determinate, within the compass whereof he is to seek; and then his

thoughts run over all the parts thereof, in the same manner as one

would sweep a room to find a jewel, or as a spaniel ranges the field

till he find a scent, or as a man should run over the alphabet to start

a rhyme." (Leviathan, 165, p. 10.)

[486] Theory of Practice, vol. i, p. 394.

[487] _Ibid._ p. 394.

[488] All association is called redintegration by Hodgson.

[489] _Ibid._ p. 400. Compare Bain, Emotions and Will, p. 377. "The

outgoings of the mind are necessarily random; the end alone is the

thing that is clear to the view, and with that there is a perception of

the fitness of every passing suggestion. The volitional energy keeps

up the attention on the active search; and the moment that anything in

point rises before the mind, it springs upon that like a wild beast

upon its prey."

[490] Compare what is said of the principle of Similarity by F. H.

Bradley, Principles of Logic, pp. 294 ff.; E. Rabier, Psychologie,

187 ff.; Paulhan, Critique Philosophique, 2me Série, i, 458; Rabier,

_ibid._ 460; Pillon, _ibid._ ii, 55; B. P. Bowne, Introduction to

Psych. Theory, 92; Ward, Encyclop. Britt. art. Psychology, p. 60;

Wahle, Vierteljahrsch. f. wiss. Philos., ix, 426-431.

[491] Dr. McCosh is accordingly only logical when he sinks similarity

in what he calls the _Law of Correlation_, according to which, when

we have discovered _a relation between things_, the idea of one tends

to bring up the others, (Psychology, the Cognitive Powers, p. 130).

The relations mentioned by this author are Identity, Whole and Parts,

Resemblance, Space, Time, Quantity, Active Property, and Cause and

Effect. If perceived relations among objects are to be treated as

grounds for their appearance before the mind, similarity has of course

no right to an exclusive, or even to a predominant, place.

[492] Cf. Bain, Senses and Intellect, 504 ff.; J. S. Mill, Note 39 to

J. Mill's Analysis; Lipps, Grundtatsachen, 97.

[493] See, for farther details, Hamilton's Reid, Appendices D** and

D***; and L. Ferri, La Psychologie de l'Association (Paris, 1883). Also

Robertson, art. Association in Encyclop. Britannica.

[494] Treatise of Human nature, part i,. § iv.

[495] Observations on Man (London, 1749).

[496] Analysis of the Phenomena of the Human Mind (1829).

[497] Hartley's Theory, 2d ed. (1790) p. xxvii.

[498] [Current, that is, in France.--W. J.]

[499] La Psychologie Angloise, p. 242.

[500] Priestley, _op. cit._ p. xxx.

[501] Review of Bains's Psychology, by J.S. Mill, in Edinb. Review,

Oct. 1, 1859, p. 293.

[502] Analysis of the Phenomena of the Human Mind, J.S. Mill's edition,

vol. i, p. 111.

[503] On the Associability of Relations between Feelings, in Principles

of Psychology, vol. i, p. 259. It is impossible to regard the "cohering

of each feeling with previously-experienced feelings of the same class,

order, genus, species, and, so far as may be, the same variety," which

Spencer calls (p. 257) 'the sole process of association of feelings,'

as any equivalent for what is commonly known as Association by

similarity.

[504] The Senses and the Intellect, pp. 491-3.

[505] See his Time and Space, chapter v, and his Theory of Practice, §§

53 to 57.

[506] Psychologie als Wissenschaft (1824), 2.

[507] Prof. Ribot, in chapter i of his 'Contemporary German

Psychology,' has given a good account of Herbart and his school, and

of Beneke, his rival and partial analogue. See also two articles on

the Herbartian Psychology, by G. F. Stout, in Mind for 1888. J. D.

Morrell's Outlines of Mental Philosophy (2d ed., London, 1862) largely

follows Herbart and Beneke. I know of no other English book which does

so.

[508] See his Grundtatsachen des Bewusstseins (1883), chap. vi _et

passim_, especially pp. 106 ff., 364.

[509] The most burdensome and utterly gratuitous of them are perhaps

Steinthal's, in his Einleitung in die Psychologie, 2te Aufl. (1881).

Cf. also G. Glogau: Steinthal's Psychologische Formeln (1886).

[510] Leçons de Philosophie, i. Psychologie, chap. xvi (1884).

[511] Mr. F. H. Bradley seems to me to have been guilty of something

very like this _ignoratio elenchi_ in the, of course, subtle and

witty but decidedly long-winded critique of the association of ideas,

contained in book ii, part ii, chap. i, of his Principles of Logic.

CHAPTER XV.[512]

THE PERCEPTION OF TIME.

In the next two chapters I shall deal with what is sometimes called

internal perception, or the perception of _time_, and of events as

occupying a date therein, especially when the date is a past one, in

which case the perception in question goes by the name of _memory_. To

remember a thing as past, it is necessary that the notion of 'past'

should be one of our 'ideas.' We shall see in the chapter on Memory

that many things come to be thought by us as past, not because of any

intrinsic quality of their own, but rather because they are associated

with other things which for us signify pastness. But how do these

things get _their_ pastness? What is the _original_ of our experience

of pastness, from whence we get the meaning of the term? It is this

question which the reader is invited to consider in the present

chapter. We shall see that we have a constant feeling _sui generis_ of

pastness, to which every one of our experiences in turn falls a prey.

To think a thing as past is to think it amongst the objects or in the

direction of the objects which at the present moment appear affected

by this quality. This is the original of our notion of past time, upon

which memory and history build their systems. And in this chapter we

shall consider this immediate sense of time alone.

If the constitution of consciousness were that of a string of bead-like

sensations and images, all separate,

"we never could have any knowledge except that of the present

instant. The moment each of our sensations ceased it would be gone

for ever; and we should be as if we had never been.... We should be

wholly incapable of acquiring experience.... Even if our ideas were

associated in trains, but only as they are in imagination, we should

still be without the capacity of acquiring knowledge. One idea, upon

this supposition, would follow another. But that would be all. Each of

our successive states of consciousness, the moment it ceased, would

be gone forever. Each of those momentary states would be our whole

being."[513]

We might, nevertheless, under these circumstances, _act_ in a rational

way, provided the mechanism which produced our trains of images

produced them in a rational order. We should make appropriate speeches,

though unaware of any word except the one just on our lips; we should

decide upon the right policy without ever a glimpse of the total

grounds of our choice. Our consciousness would be like a glow-worm

spark, illuminating the point it immediately covered, but leaving all

beyond in total darkness. Whether a very highly developed practical

life be possible under such conditions as these is more than doubtful;

it is, however, conceivable.

I make the fanciful hypothesis merely to set off our real nature by the

contrast. Our feelings are not thus contracted, and our consciousness

never shrinks to the dimensions of a glow-worm spark. _The knowledge

of some other part of the stream, past or future, near or remote, is

always mixed in with our knowledge of the present thing._

A simple sensation, as we shall hereafter see, is an abstraction, and

all our concrete states of mind are representations of objects with

some amount of complexity. Part of the complexity is the echo of the

objects just past, and, in a less degree, perhaps, the foretaste of

those just to arrive. Objects fade out of consciousness slowly. If the

present thought is of ABCDEFG, the next one will be of BCDEFGH, and

the one after that of CDEFGHI--the lingerings of the past dropping

successively away, and the incomings of the future making up the loss.

These lingerings of old objects, these incomings of new, are the germs

of memory and expectation, the retrospective and the prospective sense

of time. They give that continuity to consciousness without which it

could not be called a stream.[514]

THE SENSIBLE PRESENT HAS DURATION.

Let any one try, I will not say to arrest, but to notice or attend to,

the _present_ moment of time. One of the most baffling experiences

occurs. Where is it, this present? It has melted in our grasp, fled ere

we could touch it, gone in the instant of becoming. As a poet, quoted

by Mr. Hodgson, says,

"Le moment où je parle est déjà loin de moi,"

and it is only as entering into the living and moving organization of

a much wider tract of time that the strict present is apprehended at

all. It is, in fact, an altogether ideal abstraction, not only never

realized in sense, but probably never even conceived of by those

unaccustomed to philosophic meditation. Reflection leads us to the

conclusion that it _must_ exist, but that it _does_ exist can never

be a fact of our immediate experience. The only fact of our immediate

experience is what Mr. E. R. Clay has well called 'the _specious_

present.' His words deserve to be quoted in full:[515]

"The relation of experience to time has not been profoundly studied.

Its objects are given as being of the present, but the part of

time referred to by the datum is a very different thing from the

conterminous of the past and future which philosophy denotes by the

name Present. The present to which the datum refers is really a part

of the past--a recent past--delusively given as being a time that

intervenes between the past and the future. Let it be named the

specious present, and let the past, that is given as being the past,

be known as the obvious past. All the notes of a bar of a song seem to

the listener to be contained in the present. All the changes of place

of a meteor seem to the beholder to be contained in the present. At

the instant of the termination of such series, no part of the time

measured by them seems to be a past. Time, then, considered relatively

to human apprehension, consists of four parts, viz., the obvious past,

the specious present, the real present, and the future. Omitting the

specious present, it consists of three ... nonentities--the past,

which does not exist, the future, which does not exist, and their

conterminous, the present; the faculty from which it proceeds lies to

us in the fiction of the specious present."

In short, the practically cognized present is no knife-edge, but

a saddle-back, with a certain breadth of its own on which we sit

perched, and from which we look in two directions into time. The unit

of composition of our perception of time is a _duration_, with a bow

and a stern, as it were--a rearward- and a forward-looking end.[516]

It is only as parts of this _duration-block_ that the relation of

_succession_ of one end to the other is perceived. We do not first feel

one end and then feel the other after it, and from the perception of

the succession infer an interval of time between, but we seem to feel

the interval of time as a whole, with its two ends embedded in it. The

experience is from the outset a synthetic datum, not a simple one; and

to sensible perception its elements are inseparable, although attention

looking back may easily decompose the experience, and distinguish its

beginning from its end.

When we come to study the perception of Space, we shall find it

quite analogous to time in this regard. Date in time corresponds

to position in space; and although we now mentally construct large

spaces by mentally imagining remoter and remoter positions, just as

we now construct great durations by mentally prolonging a series of

successive dates, yet the original experience of both space and time is

always of something already given as a unit, inside of which attention

afterward discriminates parts in relation to each other. Without

the parts already given as _in_ a time and _in_ a space, subsequent

discrimination of them could hardly do more than perceive them as

_different_ from each other; it would have no motive for calling the

difference temporal order in this instance and spatial position in that.

And just as in certain experiences we may be conscious of an extensive

space full of objects, without locating each of them distinctly

therein; so, when many impressions follow in excessively rapid

succession in time, although we may be distinctly aware that they

occupy some duration, and are not simultaneous, we may be quite at

a loss to tell which comes first and which last; or we may even

invert their real order in our judgment. In complicated reaction-time

experiments, where signals and motions, and clicks of the apparatus

come in exceedingly rapid order, one is at first much perplexed in

deciding what the order is, yet of the fact of its occupancy of time we

are never in doubt.

ACCURACY OF OUR ESTIMATE OF SHORT DURATIONS.

We must now proceed to an account of the _facts_ of time-perception in

detail as preliminary to our speculative conclusion. Many of the facts

are matters of patient experimentation, others of common experience.

First of all, we note a marked _difference between the elementary

sensations of duration and those of space_. The former have a much

narrower range; the time-sense may be called a myopic organ, in

comparison with the eye, for example. The eye sees rods, acres, even

miles, at a single glance, and these totals it can afterward subdivide

into an almost infinite number of distinctly identified parts. The

units of duration, on the other hand, which the time-sense is able to

take in at a single stroke, are groups of a few seconds, and within

these units very few subdivisions--perhaps forty at most, as we

shall presently see--can be clearly discerned. The durations we have

practically most to deal with--minutes, hours, and days--have to be

symbolically conceived, and constructed by mental addition, after the

fashion of those extents of hundreds of miles and upward, which in the

field of space are beyond the range of most men's practical interests

altogether. To 'realize' a quarter of a mile we need only look out of

the window and _feel_ its length by an act which, though it may in part

result from organized associations, yet seems immediately performed. To

realize an hour, we must count 'now!--now!--now!--now!--' indefinitely.

Each 'now' is the feeling of a separate _bit_ of time, and the exact

sum of the bits never makes a very clear impression on our mind.

How many bits can we clearly apprehend at once? Very few if they are

long bits, more if they are extremely short, most if they come to us in

compound groups, each including smaller bits of its own.

Hearing is the sense by which the subdivision of durations is most

sharply made. Almost all the experimental work on the time-sense has

been done by means of strokes of sound. How long a series of sounds,

then, can we group in the mind so as not to confound it with a longer

or a shorter series?

Our spontaneous tendency is to break up any monotonously given series

of sounds into some sort of a rhythm. We involuntarily accentuate every

second, or third, or fourth beat, or we break the series in still more

intricate ways. Whenever we thus grasp the impressions in rhythmic

form, we can identify a longer string of them without confusion.

Each variety of verse, for example, has its 'law'; and the recurrent

stresses and sinkings make us feel with peculiar readiness the lack of

a syllable or the presence of one too much. Divers verses may again be

bound together in the form of a stanza, and we may then say of another

stanza, "Its second verse differs by so much from that of the first

stanza," when but for the felt stanza-form the two differing verses

would have come to us too separately to be compared at all. But these

superposed systems of rhythm soon reach their limit. In music, as

Wundt[517] says, "while the measure may easily contain 12 changes of

intensity of sound (as in 12/8 time), the rhythmical group may embrace

6 measures, and the period consist of 4, exceptionally of 5 [8?]

groups."

Wundt and his pupil Dietze have both tried to determine experimentally

the _maximal extent of our immediate distinct consciousness for

successive impressions._

Wundt found[518] that twelve impressions could be distinguished clearly

as a united cluster, provided they were caught in a certain rhythm

by the mind, and succeeded each other at intervals not smaller than

0.3 and not larger than 0.5 of a second. This makes the total time

distinctly apprehended to be equal to from 3.6 to 6 seconds.

Dietze[519] gives larger figures. The most favorable intervals for

clearly catching the strokes were when they came at from 0.3 second

to 0.18 second apart. _Forty_ strokes might then be remembered as a

whole, and identified without error when repeated, provided the mind

grasped them in five sub-groups of eight, or in eight sub-groups of

five strokes each. When no grouping of the strokes beyond making

_couples_ of them by the attention was allowed--and practically it was

found impossible not to group them in at least this simplest of all

ways--16 was the largest number that could be clearly apprehended as a

whole.[520] This would make 40 times 0.8 second, or 12 seconds, to be

the _maximum filled duration_ of which we can be both _distinctly and

immediately_ aware.

The maximum unfilled, or _vacant duration_, seems to lie within the

same objective range. Estel and Mehner, also working in Wundt's

laboratory, found it to vary from 5 or 6 to 12 seconds, and perhaps

more. The differences seemed due to practice rather than to

idiosyncrasy.[521]

These figures may be roughly taken to stand for the most important part

of what, with Mr. Clay, we called, a few pages back, the _specious

present_. The specious present has, in addition, a vaguely vanishing

backward and forward fringe; but its nucleus is probably the dozen

seconds or less that have just elapsed.

If these are the maximum, what, then, is the _minimum_ amount of

duration which we can distinctly feel?

The smallest figure experimentally ascertained was by Exner, who

distinctly heard the doubleness of two successive clicks of a Savart's

wheel, and of two successive snaps of an electric spark, when their

interval was made as small as about 1/500 of a second.[522]

With the eye, perception is less delicate. Two sparks, made to fall

beside each other in rapid succession on the centre of the retina,

ceased to be recognized as successive by Exner when their interval fell

below 0.044''.[523]

Where, as here, the succeeding impressions are only two in number,

we can easiest perceive the interval between them. President Hall,

who experimented with a modified Savart's wheel, which gave clicks in

varying number and at varying intervals, says:[524]

"In order that their discontinuity may be clearly perceived, four or

even three clicks or beats must be farther apart than two need to be.

When two are easily distinguished, three or four separated by the

same interval ... are often confidently pronounced to be two or three

respectively. It would be well if observations were so directed as to

ascertain, at least up to ten or twenty, the increase [of interval]

required by each additional click in a series for the sense of

discontinuity to remain constant throughout."[525]

Where the first impression falls on one sense, and the second on

another, the perception of the intervening time tends to be less

certain and delicate, and it makes a difference which impression comes

first. Thus, Exner found[526] the smallest perceptible interval to be,

in seconds:

From sight to touch 0.071

From touch to sight 0.053

From sight to hearing 0.16

From hearing to sight 0.06

From one ear to another 0.064

_To be conscious of a time interval at all is one thing; to tell

whether it be shorter or longer than another interval is a different

thing._ A number of experimental data are on hand which give us a

measure of the delicacy of this latter perception. The problem is that

of the _smallest difference between two times_ which we can perceive.

The difference is at its minimum when the times themselves are very

short. Exner,[527] reacting as rapidly as possible with his foot,

upon a signal seen by the eye (spark), noted all the reactions which

seemed to him either slow or fast in the making. He thought thus that

deviations of about 1/100 of a second either way from the average were

correctly noticed by him at the time. The average was here 0.1840''.

Hall and Jastrow listened to the intervals between the clicks of

their apparatus. Between two such equal intervals of 4.27'' each, a

middle interval was included, which might be made either shorter or

longer than the extremes. "After the series had been heard two or

even three times, no impression of the relative length of the middle

interval would often exist, and only after hearing the fourth and last

[repetition of the series] would the judgment incline to the _plus_ or

_minus_ side. Inserting the variable between two invariable and like

intervals greatly facilitated judgment, which between two unlike terms

is far less accurate."[528] Three observers in these experiments made

no error when the middle interval varied 1/60 from the extremes. When

it varied 1/120, errors occurred, but were few. This would make the

minimum _absolute_ difference perceived as large as 0.355''.

This minimum absolute difference, of course, increases as the times

compared grow long. Attempts have been made to ascertain what _ratio_

it bears to the times themselves. According to Fechner's 'Psychophysic

Law' it ought always to bear the same ratio. Various observers,

however, have found this not to be the case.[529] On the contrary,

very interesting _oscillations_ in the accuracy of judgment and in the

direction of the error--oscillations dependent upon the absolute amount

of the times compared--have been noticed by all who have experimented

with the question. Of these a brief account may be given.

In the first place, _in every list of intervals experimented with there

will be found what Vierordt calls an_ 'INDIFFERENCE-POINT;' that is to

say, an interval which we judge with maximum accuracy, a time which we

tend to estimate as neither longer or shorter than it really is, and

away from which, in both directions, errors increase their size.[530]

This time varies from one observer to another, but its average is

remarkably constant, as the following table shows.[531]

The times, noted by the ear, and the average indifference-points (given

in seconds) were, for--

Wundt[532] 0.72

Kollert[533] 0.75

Estel (probably) 0.75

Mehner 0.71

Stevens[534] 0.71

Mach[535] 0.35

Buccola (about)[536] 0.40

The odd thing about these figures is the recurrence they show in so

many men of about three fourths of a second, as the interval of time

most easy to catch and reproduce, Odder still, both Estel and Mehner

found that _multiples_ of this time were more accurately reproduced

than the time-intervals of intermediary length;[537] and Glass found a

certain periodicity, with the constant increment of 1.25 sec., in his

observations. There would seem thus to exist something like a periodic

or rhythmic sharpening of our time-sense, of which the period differs

somewhat from one observer to the next.

_Our sense of time_, like other senses, _seems subject to the law of

contrast_. It appeared pretty plainly in Estel's observations that an

interval sounded shorter if a long one had immediately preceded it, and

longer when the opposite was the case.

Like other senses, too, _our sense of time is sharpened by practice_.

Mehner ascribes almost all the discrepancies between other observers

and himself to this cause alone.[538]

_Tracts of time filled_ (with clicks of sound) _seem longer than vacant

ones_ of the same duration, when the latter does not exceed a second or

two.[539] This, which reminds one of what happens with spaces seen by

the eye, becomes reversed when longer times are taken. It is, perhaps,

in accordance with this law that a _loud_ sound, limiting a short

interval of time, makes it appear longer, a _slight_ sound shorter. In

comparing intervals marked out by sounds, we must take care to keep the

sounds uniform.[540]

* * * * *

There is a certain emotional _feeling_ accompanying the intervals

of time, as is well known in music. _The sense of haste goes with

one measure of rapidity, that of delay with another;_ and these two

feelings harmonize with different mental moods. Vierordt listened

to series of strokes performed by a metronome at rates varying from

40 to 200 a minute, and found that they very naturally fell into

seven categories, from 'very slow' to 'very fast.'[541] Each category

of feeling included the intervals following each other within a

certain range of speed, and no others. This is a qualitative, not

a quantitative judgment--an æsthetic judgment, in fact. The middle

category, of speed that was neutral, or, as he calls it, 'adequate,'

contained intervals that were grouped about 0.62 second, and Vierordt

says that this made what one might almost call an _agreeable_ time.[542]

The feeling of time and accent in music, of rhythm, is quite

independent of that of melody. Tunes with marked rhythm can be readily

recognized when simply drummed on the table with the finger-tips.

WE HAVE NO SENSE FOR EMPTY TIME.

Although subdividing the time by beats of sensation aids our accurate

knowledge of the amount of it that elapses, such subdivision does not

seem at the first glance essential to our perception of its flow.

Let one sit with closed eyes and, abstracting entirely from the

outer world, attend exclusively to the passage of time, like one who

wakes, as the poet says, "to hear time flowing in the middle of the

night, and all things moving to a day of doom." There seems under

such circumstances as these no variety in the material content of our

thought, and what we notice appears, if anything, to be the pure series

of durations budding, as it were, and growing beneath our indrawn

gaze. Is this really so or not? The question is important, for, if the

experience be what it roughly seems, we have a sort of special sense

for pure time--a sense to which empty duration is an adequate stimulus;

while if it be an illusion, it must be that our perception of time's

flight, in the experiences quoted, is due to the _filling_ of the time,

and to our _memory_ of a content which it had a moment previous, and

which we feel to agree or disagree with its content now.

It takes but a small exertion of introspection to show that the

latter alternative is the true one, and that _we can no more intuit

a duration than we can intuit an extension, devoid of all sensible

content_. Just as with closed eyes we perceive a dark visual field

in which a curdling play of obscurest luminosity is always going on;

so, be we never so abstracted from distinct outward impressions, we

are always inwardly immersed in what Wundt has somewhere called the

twilight of our general consciousness. Our heart-beats, our breathing,

the pulses of our attention, fragments of words or sentences that pass

through our imagination, are what people this dim habitat. Now, all

these processes are rhythmical, and are apprehended by us, as they

occur, in their totality; the breathing and pulses of attention, as

coherent successions, each with its rise and fall; the heart-beats

similarly, only relatively far more brief; the words not separately,

but in connected groups. In short, empty our minds as we may, some

form of _changing process_ remains for us to feel, and cannot be

expelled. And along with the sense of the process and its rhythm goes

the sense of the length of time it lasts. Awareness of _change_ is

thus the condition on which our perception of time's flow depends; but

there exists no reason to suppose that empty time's own changes are

sufficient for the awareness of change to be aroused. The change must

be of some concrete sort--an outward or inward sensible series, or a

process of attention or volition.[543]

And here again we have an analogy with space. The earliest form of

distinct space-perception is undoubtedly that of a movement over

some one of our sensitive surfaces, and this movement is originally

given as a simple whole of feeling, and is only decomposed into its

elements--successive positions successively occupied by the moving

body--when our education in discrimination is much advanced. But a

movement is a change, a process; so we see that in the time-world

and the space-world alike the first known things are not elements,

but combinations, not separate units, but wholes already formed.

The condition of _being_ of the wholes may be the elements; but the

condition of our _knowing_ the elements is our having already felt the

wholes as wholes.

In the experience of watching empty time flow--'empty' to be taken

hereafter in the relative sense just set forth--we tell it off in

pulses. We say 'now! now! now!' or we count 'more! more! more!' as we

feel it bud. This composition out of units of duration is called the

law of time's _discrete flow_. The discreteness is, however, merely due

to the fact that our successive acts of _recognition_ or _apperception_

of _what_ it is are discrete. The sensation is as continuous as any

sensation can be. All continuous sensations are _named_ in beats. We

notice that a certain finite 'more' of them is passing or already past.

To adopt Hodgson's image, the sensation is the measuring-tape, the

perception the dividing-engine which stamps its length. As we listen

to a steady sound, we _take it in_ in discrete pulses of recognition,

calling it successively 'the same! the same! the same!' The case stands

no otherwise with time.

After a small number of beats our impression of the amount we have

told off becomes quite vague. Our only way of knowing it accurately

is by counting, or noticing the clock, or through some other symbolic

conception.[544] When the times exceed hours or days, the conception

is absolutely symbolic. We think of the amount we mean either solely

as a _name_, or by running over a few salient _dates_ therein, with

no pretence of imagining the full durations that lie between them.

No one has anything like a _perception_ of the greater length of the

time between now and the first century than of that between now and

the tenth. To an historian, it is true, the longer interval will

suggest a host of additional dates and events, and so appear a more

_multitudinous_ thing. And for the same reason most people will think

they directly perceive the length of the past fortnight to exceed that

of the past week. But there is properly no comparative time _intuition_

in these cases at all. It is but dates and events. _representing_ time;

their abundance _symbolizing_ its length. I am sure that this is so,

even where the times compared are no more than an hour or so in length.

It is the same with Spaces of many miles, which we always compare with

each other by the numbers which measure them.[545]

From this we pass naturally to speak of certain familial variations

in our estimation of lengths of time. _In general, a time filled with

varied and interesting experiences seems short in passing, but long as

we look back. On the other hand, a tract of time empty of experiences

seems long in passing, but in retrospect short._ A week of travel and

sight-seeing may subtend an angle more like three weeks in the memory;

and a month of sickness hardly yields more memories than a day. The

length in retrospect depends obviously on the multitudinousness of the

memories which the time affords. Many objects, events, changes, many

subdivisions, immediately widen the view as we look back. Emptiness,

monotony, familiarity, make it shrivel up. In Von Holtei's 'Vagabonds'

one Anton is described as revisiting his native village.

"Seven years," he exclaims, "seven years since I ran away! More like

seventy it seems, so much has happened. I cannot think of it all

without becoming dizzy--at any rate not now. And yet again, when I

look at the village, at the church-tower, it seems as if I could

hardly have been seven days away."

Prof. Lazarus[546] (from whom I borrow this quotation), thus explains

both of these contrasted illusions by our principle of the awakened

memories being multitudinous or few:

"The circle of experiences, widely extended, rich in variety, which

he had in view on the day of his leaving the village rises now in his

mind as its image lies before him. And with it--in rapid succession

and violent motion, not in chronologic order, or from chronologic

motives, but suggesting each other by all sorts of connections--arise

massive images of all his rich vagabondage and roving life. They roll

and wave confusedly together, first perhaps one from the first year,

then from the sixth, soon from the second, again from the fifth, the

first, etc., until it seems as if seventy years must have been there,

and he reels with the fulness of his vision.... Then the inner eye

turns away from all this past. The outer one turns to the village,

especially to the church-tower. The sight of it calls back the old

sight of it, so that the consciousness is filled with that alone, or

almost alone. The one vision compares itself with the other, and looks

so near, so unchanged, that it seems as if only a week of time could

have come between."

_The same space of time seems shorter as we grow older_--that is, the

days, the months, and the years do so; whether the hours do so is

doubtful, and the minutes and seconds to all appearance remain about

the same.

"Whoever counts many lustra in his memory need only question himself

to find that the last of these, the past five years, have sped much

more quickly than the preceding periods of equal amount. Let any one

remember his last eight or ten school years: it is the space of a

century. Compare with them the last eight or ten years of life: it is

the space of an hour."

So writes Prof. Paul Janet,[547] and gives a solution which can hardly

be said to diminish the mystery. There is a law, he says, by which

the apparent length of an interval at a given epoch of a man's life

is proportional to the total length of the life itself. A child of 10

feels a year as 1/10 of his whole life--a man of 50 as 1/50, the whole

life meanwhile apparently preserving a constant length. This formula

roughly expresses the phenomena, it is true, but cannot possibly be

an elementary psychic law; and it is certain that, in great part at

least, the foreshortening of the years as we grow older is due to

the monotony of memory's content, and the consequent simplification

of the backward-glancing view. In youth we may have an absolutely

new experience, subjective or objective, every hour of the day.

Apprehension is vivid, retentiveness strong, and our recollections of

that time, like those of a time spent in rapid and interesting travel,

are of something intricate, multitudinous, and long-drawn-out. But

as each passing year converts some of this experience into automatic

routine which we hardly note at all, the days and the weeks smooth

themselves out in recollection to contentless units, and the years grow

hollow and collapse.

So much for the apparent shortening of tracts of time in _retrospect_.

They shorten _in passing_ whenever we are so fully occupied with

their content as not to note the actual time itself. A day full of

excitement, with no pause, is said to pass 'ere we know it.' On the

contrary, a day full of waiting, of unsatisfied desire for change, will

seem a small eternity. _Tædium, ennui, Langweile, boredom,_ are words

for which, probably, every language known to man has its equivalent.

It comes about whenever, from the relative emptiness of content

of a tract of time, we grow attentive to the passage of the time

itself. Expecting, and being ready for, a new impression to succeed;

when it fails to come, we get an empty time instead of it; and such

experiences, ceaselessly renewed, make us most formidably aware of the

extent of the mere time itself.[548] Close your eyes and simply wait

to hear somebody tell you that a minute has elapsed. The full length

of your leisure with it seems incredible. You engulf yourself into

its bowels as into those of that interminable first week of an ocean

voyage, and find yourself wondering that history can have overcome

many such periods in its course. All because you attend so closely

to the mere feeling of the time _per se_, and because your attention

to that is susceptible of such fine-grained successive subdivision.

The _odiousness_ of the whole experience comes from its insipidity;

for _stimulation_ is the indispensable requisite for pleasure in an

experience, and the feeling of bare time is the least stimulating

experience we can have.[549] The sensation of tæedium is a _protest_,

says Volkmann, against the entire present.

Exactly parallel variations occur in our consciousness of space. A

road we walk back over, hoping to find at each step an object we have

dropped, seems to us longer than when we walked over it the other way.

A space we measure by pacing appears longer than one we traverse with

no thought of its length. And in general an amount of space attended to

in itself leaves with us more impression of spaciousness than one of

which we only note the content.[550]

I do not say that _everything_ in these fluctuations of estimate can be

accounted for by the time's content being crowded and interesting, or

simple and tame. Both in the shortening of time by old age and in its

lengthening by _ennui_ some deeper cause _may_ be at work. This cause

can only be ascertained, if it exist, by finding out _why we perceive

time at all_. To this inquiry let us, though without much hope, proceed.

THE FEELING OF PAST TIME IS A PRESENT FEELING.

If asked why we perceive the light of the sun, or the sound of an

explosion, we reply, "Because certain outer forces, ether-waves or

air-waves, smite upon the brain, awakening therein changes, to which

the conscious perceptions, light and sound, respond." But we hasten

to add that neither light nor sound _copy_ or _mirror_ the ether- or

air-waves; they represent them only symbolically. The _only_ case, says

Helmholtz, in which such copying occurs, and in which

"our perceptions can truly correspond with outer reality, is that of

the _tune-succession_ of phenomena. Simultaneity, succession, and

the regular return of simultaneity or succession, can obtain as well

in sensations as in outer events. Events, like our perceptions of

them, take place in time, so that the time-relations of the latter

can furnish a true copy of those of the former. The sensation of the

thunder follows the sensation of the lightning just as the sonorous

convulsing of the air by the electric discharge reaches the observer's

place later than that of the luminiferous ether."[551]

One experiences an almost instinctive impulse, in pursuing such

reflections as these, to follow them to a sort of crude speculative

conclusion, and to think that he has at last got the mystery of

cognition where, to use a vulgar phrase, 'the wool is short.' What

more natural, we say, than that the sequences and durations of things

_should_ become known? The succession of the outer forces stamps

itself as a like succession upon the brain. The brain's successive

changes are copied exactly by correspondingly successive pulses of

the mental stream. The mental stream, feeling itself, must feel the

time-relations of its own states. But as these are copies of the

outward time-relations, so must it know them too. That is to say, these

latter time-relations arouse their own cognition; or, in other words,

the mere existence of time in those changes out of the mind which

affect the mind is a sufficient cause why time is perceived by the mind.

This philosophy is unfortunately too crude. Even though we _were_

to conceive the outer successions as forces stamping their image

on the brain, and the brain's successions as forces stamping their

image on the mind,[552] still, between the mind's own changes _being_

successive, and _knowing their own succession_, lies as broad a chasm

as between the object and subject of any case of cognition in the

world. _A succession of feelings, in and of itself, is not a feeling

of succession. And since, to our successive feelings, a feeling of

their own succession is added, that must be treated as an additional

fact requiring its own special elucidation,_ which this talk about

outer time-relations stamping copies of themselves within, leaves all

untouched.

I have shown, at the outset of the article, that what is past, to be

known as past, must be known _with_ what is present, and _during_ the

'present' spot of time. As the clear understanding of this point has

some importance, let me, at the risk of repetition, recur to it again.

Volkmann has expressed the matter admirably, as follows:

"One might be tempted to answer the question of the origin of the

time-idea by simply pointing to the train of ideas, whose various

members, starting from the first, successively attain to full

clearness. But against this it must be objected that the successive

ideas are not yet the idea of succession, because succession _in_

thought is not the thought _of_ succession. If idea A follows idea B,

consciousness simply exchanges one for another. That B _comes after_

A is for our consciousness a non-existent fact; for this _after_ is

given neither in B nor in A; and no third idea has been supposed.

The thinking of the sequence of B upon A is another kind of thinking

from that which brought forth A and then brought forth B; and this

first kind of thinking is absent so long as merely the thinking of A

and the thinking of B are there. In short, when we look at the matter

sharply, we come to this antithesis, that if _A_ and B are to be

represented _as occurring in succession_ they must be _simultaneously

represented_; if we are to think _of_ them as one after the other, we

must _think_ them both at once."[553]

If we represent the actual time-stream of our thinking by an horizontal

line, the thought _of_ the stream or of any segment of its length,

past, present, or to come, might be figured in a perpendicular

raised upon the horizontal at a certain point. The length of this

perpendicular stands for a certain object or content, which in this

case is the time thought of, and all of which is thought of together at

the actual moment of the stream upon which the perpendicular is raised.

Mr. James Ward puts the matter very well in his masterly article

'Psychology' in the ninth edition of the Encyclopædia Britannica, page

64. He says:

"We may, if we represent succession as a line, represent simultaneity

as a second line at right angles to the first; empty time--or

time-length without time-breadth, we may say--is a mere abstraction.

Now, it is with the former line that we have to do in treating of

time as it is, and with the latter in treating of our intuition of

time, where, just as in a perspective representation of distance, we

are confined to lines in a plane at right angles to the actual line

of depth. In a succession of events, say of sense-impressions, A B

C D E..., the presence of B means the absence of A and C, but the

presentation of this succession involves the simultaneous presence

in some mode or other of two or more of the presentations A B C D.

In reality, past, present, and future are differences in time, but

in presentation all that corresponds to these differences is in

consciousness simultaneously."

There is thus a sort of _perspective projection_ of past objects upon

present consciousness, similar to that of wide landscapes upon a

camera-screen.

And since we saw a while ago that our maximum distinct _intuition_ of

duration hardly covers more than a dozen seconds (while our maximum

vague intuition is probably not more than that of a minute or so), we

must suppose that _this amount of duration is pictured fairly steadily

in each passing instant of consciousness_ by virtue of some fairly

constant feature in the brain-process to which the consciousness is

tied. _This feature of the brain-process, whatever it be, must be the

cause of our perceiving the fact of time at all._[554] The duration

thus steadily perceived is hardly more than the 'specious present,'

as it was called a few pages back. Its _content_ is in a constant

flux, events dawning into its forward end as fast as they fade out

of its rearward one, and each of them changing its time-coefficient

from 'not yet,' or 'not quite yet,' to 'just gone' or 'gone,' as it

passes by. Meanwhile, the specious present, the intuited duration,

stands permanent, like the rainbow on the waterfall, with its own

quality unchanged by the events that stream through it. Each of these,

as it slips out, retains the power of being reproduced; and when

reproduced, is reproduced with the duration and neighbors which it

originally had. Please observe, however, that the reproduction of an

event, _after_ it has once completely dropped out of the rearward end

of the specious present, is an entirely different psychic fact from

its direct perception in the specious present as a thing immediately

past. A creature might be entirely devoid of _reproductive_ memory,

and yet have the time-sense; but the latter would be limited, in his

case, to the few seconds immediately passing by. Time older than that

he would never recall. I assume reproduction in the text, because I am

speaking of human beings who notoriously possess it. Thus memory gets

strewn with _dated_ things--dated in the sense of being before or after

each other.[555] The date of a thing is a mere relation of _before_ or

_after_ the present thing or some past or future thing. Some things

we date simply by mentally tossing them into the past or future

_direction_. So in space we think of England as simply to the eastward,

of Charleston as lying south. But, again, we may date an event exactly,

by fitting it between two terms of a past or future series explicitly

conceived, just as we may accurately think of England or Charleston

being just so many miles away.[556]

The things and events thus vaguely or exactly dated become

thenceforward those signs and symbols of longer time-spaces, of which

we previously spoke. According as we think of a multitude of them, or

of few, so we imagine the time they represent to be long or short.

But _the original paragon and prototype of all conceived times is the

specious present, the short duration of which we are immediately and

incessantly sensible._

TO WHAT CEREBRAL PROCESS IS THE SENSE OF TIME DUE?

_Now, to what element in the brain-process may this sensibility be

due?_ It cannot, as we have seen, be due to the mere duration itself of

the process; it must be due to an element present at every moment of

the process, and this element must bear the same inscrutable _sort_ of

relation to its correlative feeling which all other elements of neural

activity bear to their psychic products, be the latter what they may.

Several suggestions have been made as to what the element is in the

case of time. Treating of them in a note,[557] I will try to express

briefly the only conclusion which seems to emerge from a study of them

and of the facts--unripe though that conclusion be.

The phenomena of 'summation of stimuli' in the nervous system prove

that each stimulus leaves some latent activity behind it which only

gradually passes away. (See above, pp. 82-85.) Psychological proof of

the same fact is afforded by those 'after-images' which we perceive

when a sensorial stimulus is gone. We may read off peculiarities in an

after-image, left by an object on the eye, which we failed to note in

the original. We may 'hark back' and take in the meaning of a sound

several seconds after it has ceased. Delay for a minute, however,

and the echo itself of the clock or the question is mute; present

sensations have banished it beyond recall. With the feeling of the

present thing there must at all times mingle the fading echo of all

those other things which the previous few seconds have supplied. Or,

to state it in neural terms, _there is at every moment a cumulation of

brain-processes overlapping each other, of which the fainter ones are

the dying phases of processes which but shortly previous were active

in a maximal degree. The_ AMOUNT OF THE OVERLAPPING _determines the

feeling of the_ DURATION OCCUPIED. WHAT EVENTS _shall appear to occupy

the duration depends on just_ WHAT PROCESSES _the overlapping processes

are._ We know so little of the intimate nature of the brain's activity

that even where a sensation monotonously endures, we cannot say that

the earlier moments of it do not leave fading processes behind which

coexist with those of the present moment. _Duration and events together

form our intuition of the specious present with its content._[558]

_Why_ such an intuition should result from such a combination of

brain-processes I do not pretend to say. All I aim at is to state the

most _elemental_ form of the psycho-physical conjunction.

I have assumed that the brain-processes are sensational ones. Processes

of active attention (see Mr. Ward's account in Footnote 556) will leave

similar fading brain-processes behind. If the mental processes are

conceptual, a complication is introduced of which I will in a moment

speak. Meanwhile, still speaking of sensational processes, a remark

of Wundt's will throw additional light on the account I give. As is

known, Wundt and others have proved that every act of perception of

a sensorial stimulus takes an appreciable time. When two different

stimuli--e.g. a sight and a sound--are given at once or nearly at

once, we have difficulty in attending to both, and may wrongly judge

their interval, or even invert their order. Now, as the result of his

experiments on such stimuli. Wundt lays down this law:[559] that of the

three possible determinations we may make of their order--

"namely, simultaneity, continuous transition, and discontinuous

transition--only the first and last are realized, _never the second_.

Invariably, when we fail to perceive the impressions as simultaneous,

we notice a shorter or longer empty time between them, _which seems

to correspond to the sinking of one of the ideas and to the rise of

the other_.... For our attention may share itself equally between

the two impressions, which will then compose one total percept [and

be simultaneously felt]; or it may be so adapted to one event as to

cause it to be perceived immediately, and then the second event can

be perceived only after a certain time of latency, during which the

attention reaches its effective maximum for it and diminishes for

the first event. In this case the events are perceived as _two_, and

in successive order--that is, as separated by a time-interval in

which attention is not sufficiently accommodated to either to bring a

distinct perception about.... While we are hurrying from one to the

other, everything between them vanishes in the twilight of general

consciousness."[560]

One might call this the _law of discontinuous succession in time, of

percepts to which we cannot easily attend at once._ Each percept then

requires a separate brain-process; and when one brain-process is at its

maximum, the other would appear perforce to be in either a waning or

a waxing phase. If our theory of the time-feeling be true, empty time

_must_ then subjectively appear to separate the two percepts, no matter

how close together they may objectively be; for, according to that

theory, the feeling of a time-duration is the immediate effect of such

an overlapping of brain-processes of different phase--wherever and

from whatever cause it may occur.

To pass, now, to conceptual processes: Suppose I think of the Creation,

then of the Christian era, then of the battle of Waterloo, all within

a few seconds. These matters have their dates far outside the specious

present. The processes by which I think them, however, all overlap.

What events, then, does the specious present seem to contain? Simply

my successive _acts of thinking_ these long-past things, not the

long-past things themselves. As the instantly-present thought may be of

a long-past thing, so the just-past thought may be of another long-past

thing. When a long-past event is reproduced in memory and conceived

with its date, the reproduction and conceiving traverse the specious

present. The immediate content of the latter is thus all my _direct

experiences_, whether subjective or objective. Some of these meanwhile

may be _representative_ of other experiences indefinitely remote.

The number of these direct experiences which the specious present

and immediately-intuited past may embrace measures the extent of

our 'primary,' as Exner calls it, or, as Richet calls it, of our

'elementary' memory.[561] The sensation resultant from the overlapping

is that of the duration which the experiences seem to fill. As is the

number of any larger set of events to that of these experiences, so we

suppose is the length of that duration to this duration. But of the

longer duration we have no direct 'realizing sense.' The variations

in our appreciation of the same amount of real time may possibly be

explained by alterations in the rate of fading in the images, producing

changes in the complication of superposed processes, to which changes

changed states of consciousness may correspond. But however _long we

may conceive_ a space of time to be, the objective amount of it which

is _directly perceived_ at any one moment by us can never exceed the

scope of our 'primary memory' at the moment in question.[562]

We have every reason to think that creatures may possibly differ

enormously in the amounts of duration which they intuitively feel,

and in the fineness of the events that may fill it. Von Bær has

indulged[563] in some interesting computations of the effect of such

differences in changing the aspect of Nature. Suppose we were able,

within the length of a second, to note 10,000 events distinctly,

instead of barely 10, as now; if our life were then destined to hold

the same number of impressions, it might be 1000 times as short. We

should live less than a month, and personally know nothing of the

change of seasons. If born in winter, we should believe in summer as

we now believe in the heats of the Carboniferous era. The motions of

organic beings would be so slow to our senses as to be inferred, not

seen. The sun would stand still in the sky, the moon be almost free

from change, and so on. But now reverse the hypothesis and suppose a

being to get only one 1000th part of the sensations that we get in

a given time, and consequently to live 1000 times as long. Winters

and summers will be to him like quarters of an hour. Mushrooms and

the swifter-growing plants will shoot into being so rapidly as to

appear instantaneous creations; annual shrubs will rise and fall

from the earth like restlessly boiling-water springs; the motions of

animals will be as invisible as are to us the movements of bullets and

cannon-balls; the sun will scour through the sky like a meteor, leaving

a fiery trail behind him, etc. That such imaginary cases (barring the

superhuman longevity) may be realized somewhere in the animal kingdom,

it would be rash to deny.

"A gnat's wings," says Mr Spencer,[564] "make ten or fifteen thousand

strokes a second. Each stroke implies a separate nervous action.

Each such nervous action or change in a nervous centre is probably

as appreciable by the gnat as is a quick movement of his arm by a

man. And if this, or anything like this, is the fact, then the time

occupied by a given external change, measured by many movements in the

one case, must seem much longer than in the other case, when measured

by one movement."

In hashish-intoxication there is a curious increase in the apparent

time-perspective. We utter a sentence, and ere the end is reached

the beginning seems already to date from indefinitely long ago. We

enter a short street, and it is as if we should never get to the end

of it. This alteration might conceivably result from an approach to

the condition of Von Bær's and Spencer's short-lived beings. If our

discrimination of successions became finer-grained, so that we noted

ten stages in a process where previously we only noted one; and if at

the same time the processes faded ten times as fast as before; we might

have a specious present of the same subjective length as now, giving us

the same time-feeling and containing as many distinguishable successive

events, but out from the earlier end of it would have dropped nine

tenths of the real events it now contains. They would have fallen into

the general reservoir of merely dated memories, reproducible at will.

The beginning of our sentences would have to be expressly recalled;

each word would appear to pass through consciousness at a tenth of its

usual speed. The condition would, in short, be exactly analogous to

the enlargement of space by a microscope; fewer real things at once in

the immediate field of view, but each of them taking up more than its

normal room, and making the excluded ones seem unnaturally far away.

Under other conditions, processes seem to fade rapidly without the

compensating increase in the subdivisibility of successions. Here

the apparent length of the specious present contracts. Consciousness

dwindles to a point, and loses all intuitive sense of the whence and

whither of its path. Express acts of memory replace rapid bird's-eye

views. In my own case, something like this occurs in extreme fatigue.

Long illnesses produce it. Occasionally, it appears to accompany

aphasia.[565] It would be vain to seek to imagine the exact

brain-change in any of these cases But we must admit the possibility

that to some extent the variations of time-estimate between youth and

age, and excitement and _ennui_, are due to such causes, more immediate

than to the one we assigned some time ago.

_But whether our feeling of the time which immediately-past_[566]

events have filled be of something long or of something short, it is

not what it is because those events are past,_ but _because they have

left behind them processes which are present. To those processes,

however caused, the mind would still respond by feeling a specious

present, with one part of it just vanishing or vanished into the past._

As the Creator is supposed to have made Adam with a navel--sign of a

birth which never occurred--so He might instantaneously make a man

with a brain in which were processes just like the 'fading' ones of an

ordinary brain. The first real stimulus after creation would set up

a process additional to these. The processes would overlap; and the

new-created man would unquestionably have the feeling, at the very

primal instant of his life, of having been in existence already some

little space of time.

Let me sum up, now, by saying that we are constantly conscious of a

certain duration--the specious present--varying in length from a few

seconds to probably not more than a minute, and that this duration

(with its content perceived as having one part earlier and the other

part later) is the original intuition of time. Longer times are

conceived by adding, shorter ones by dividing, portions of this vaguely

bounded unit, and are habitually thought by us symbolically. Kant's

notion of an _intuition_ of objective time as an infinite necessary

continuum has nothing to support it. The _cause_ of the intuition which

we really have cannot be the _duration_ of our brain-processes or our

mental changes. That duration is rather the _object_ of the intuition

which, being realized at every moment of such duration, must be due

to a permanently present cause. This cause--probably the simultaneous

presence of brain-processes of different phase--fluctuates; and hence a

certain range of variation in the amount of the intuition, and in its

subdivisibility, accrues.

FOOTNOTES:

[512] This chapter is reprinted almost verbatim from the Journal of

Speculative Philosophy, vol. xx, p. 374.

[513] James Mill, Analysis, vol. x, p. 319 (J. S. Mill's edition).

[514] "What I find, when I look at consciousness at all, is, that

what I cannot divest myself of, or not have in consciousness, if I

have consciousness at all, is a sequence of different feelings....

The simultaneous perception of both sub-feelings, whether as parts

of a coexistence or of a sequence, is the total feeling--the minimum

of consciousness--and this minimum has duration.... Time-duration,

however, is inseparable from the minimum, notwithstanding that, in

an isolated moment, we could not tell which part of it came first,

which last.... We do not require to know that the sub-feelings come

in sequence, first one, then the other; nor to know what coming in

sequence means. But we have, in any artificially isolated minimum of

consciousness, the _rudiments_ of the perception of former and latter

in time, in the sub-feeling that grows fainter, and the sub-feeling

that grows stronger, and the change between them....

"In the next place, I remark that the rudiments of memory are involved

in the minimum of consciousness. The first beginnings of it appear in

that minimum, just as the first beginnings of perception do. As each

member of the change or difference which goes to compose that minimum

is the rudiment of a single perception, so the priority of one member

to the other, although both are given to consciousness in one empirical

present moment, is the rudiment of memory. The fact that the minimum

of consciousness is difference or change in feelings, is the ultimate

explanation of memory as well as of single perceptions. A former and a

latter are included in the minimum of consciousness; and this is what

is meant by saying that all consciousness is in the form of _time_, or

that time is the form of feeling, the form of sensibility. Crudely and

popularly we divide the course of time into past, present, and future;

but, strictly speaking, there is no present; it is composed of past

and future divided by an indivisible point or instant. That instant,

or time-point, is the strict _present_. What we call, loosely, the

present, is an empirical portion of the course of time, containing at

least a minimum of consciousness, in which the instant of change is the

present time-point.... If we take this as the present time-point, it is

clear that the minimum of feeling contains two portions--a sub-feeling

that goes and a sub-feeling that comes. One is remembered, the other

imagined. The limits of both are indefinite at beginning and end of the

minimum, and ready to melt into other minima, proceeding from other

stimuli.

"Time and consciousness do not come to us ready marked out into minima;

we have to do that by reflection, asking ourselves, What is the least

empirical moment of consciousness? That least empirical moment is what

we usually call the present moment; and even this is too minute for

ordinary use; the present moment is often extended practically to a few

seconds, or even minutes, beyond which we specify what length of time

we mean, as the present hour, or day, or year, or century.

"But this popular way of thinking imposes itself on great numbers even

of philosophically-minded people, and they talk about the _present_ as

if it was a _datum_--as if time came to us marked into present periods

like a measuring-tape." (S. H. Hodgson: Philosophy of Reflection, vol.

i, pp. 248-254.)

"The representation of time agrees with that of space in that a certain

amount of it must be presented together--included between its initial

and terminal limit. A continuous ideation, flowing from one point

to another, would indeed _occupy_ time, but not _represent_ it, for

it would exchange one element of succession for another instead of

grasping the whole succession at once. Both points--the beginning and

the end--are equally essential to the conception of time, and must be

present with equal clearness together." (Herbart: Psychol. als W., §

115.)

"Assume that ... similar pendulum-strokes follow each other at regular

intervals in a consciousness otherwise void. When the first one is

over, an image of it remains in the fancy until the second succeeds.

This, then, reproduces the first by virtue of the law of association by

similarity, but at the same time meets with the aforesaid persisting

image.... Thus does the simple repetition of the sound provide all

the elements of time-perception. The first sound [as it is recalled

by association] gives the beginning, the second the end, and the

persistent image in the fancy represents the length of the interval.

At the moment of the second impression, the entire time-perception

exists at once, for then all its elements are presented together, the

second sound and the image in the fancy immediately, and the first

impression by reproduction. But, in the same act, we are aware of a

state in which only the first sound existed, and of another in which

only its image existed in the fancy. Such a consciousness as this _is_

that of time.... _In it no succession of ideas takes place._" (Wundt:

Physiol. Psych., 1st ed. pp. 681-2.) Note here the assumption that the

_persistence_ and the _reproduction_ of an impression are two processes

which may go on simultaneously. Also that Wundt's description is merely

an _attempt to analyze the 'deliverance'_ of a time-perception, and no

_explanation of the manner in which it comes about_.

[515] The Alternative, p. 167.

[516] Locke, in his dim way, derived the sense of duration from

reflection on the succession of our ideas (Essay, book ii, chap. xiv,

§ 3; chap. xv, § 12). Reid justly remarks that if ten successive

elements are to make duration, "then one must make duration, otherwise

duration must be made up of parts that have no duration, which is

impossible.... I conclude, therefore, that there must be duration in

every single interval or element of which the whole duration is made

up. Nothing, indeed, is more certain than that every elementary part of

extension must have extension. Now, it must be observed that in these

elements of duration, or single intervals of successive ideas, there

is no succession of ideas, yet we must conceive them to have duration;

whence we may conclude with certainty that _there is a conception

of duration where there is no succession of ideas in the mind._"

(Intellectual Powers, essay iii, chap. v.) "Qu'on ne cherche point,"

says Royer-Collard in the Fragments added to Jouffroy's Translation of

Reid, "la durée dans la succession; on ne l'y trouvera jamais; la durée

a précédé la succession; la notion de la durée a précédé la notion de

la succession. Elle en est donc tout-à-fait indépendante, dira-t-on?

Oui, elle en est tout-à-fait indépendante."

[517] Physiol. Psych., ii, 54, 55.

[518] _Ibid._ ii, 213.

[519] Philosophische Studien, ii, 362.

[520] _Counting_ was of course not permitted. It would have given

a symbolic concept and no intuitive or immediate perception of the

totality of the series. With counting we may of course compare together

series of any length--series whose beginnings have faded from our mind,

and of whose totality we retain no sensible impression at all. To

count a series of clicks is an altogether different thing from merely

perceiving them as discontinuous. In the latter case we need only be

conscious of the bits of empty duration between them; in the former we

must perform rapid acts of association between them and as many names

of numbers.

[521] Estel in Wundt's Philosophische Studien, ii, 50. Mehner, _ibid._

ii, 571. In Dietze's experiments even numbers of strokes were better

caught than odd ones, by the ear. The _rapidity of their sequence_

had a great influence on the result. At more than 4 seconds apart

it was impossible to perceive series of them as units in all (cf.

Wundt, Physiol. Psych., ii, 214). They were simply counted as so

many individual strokes. Below 0.21 to 0.11 second, according to the

observer, judgment again became confused. It was found that the rate of

succession most favorable for grasping long series was when the strokes

were sounded at intervals of from 0.3'' to 0.18' apart. Series of 4, 6,

8, 16 were more easily identified than series of 10, 12, 14, 18. The

latter could hardly be clearly grasped at all. Among odd numbers 3, 5,

7 were the series easiest caught; next, 9, 15; hardest of all, 11 and

13; and 17 was impossible to apprehend.

[522] The exact interval of the sparks was 0.00205''. The doubleness

of their snap was usually replaced by a single-seeming sound when it

fell to 0.00198'', the sound becoming _louder_ when the sparks seemed

simultaneous. The _difference_ between these two intervals is only

7/100000 of a second; and, as Exner remarks, our ear and brain must be

wonderfully efficient organs to get distinct feelings from so slight an

objective difference as this. See Pflüger's Archiv, Bd. xi.

[523] _Ibid._ p. 407. When the sparks fell so close together that their

irradiation-circles overlapped, they appeared like _one spark moving_

from the position of the first to that of the second; and they might

then follow each other as close as 0.015'' without the _direction

of the movement_ ceasing to be clear. When one spark fell on the

centre, the other on the margin, of the retina, the time-interval for

successive apprehension had to be raised to 0.076''.

[524] Hall and Jastrow: Studies of Rhythm. Mind, xi, 58.

[525] Nevertheless, multitudinous impressions may be felt as

discontinuous, though separated by excessively minute intervals of

time. Grünhagen says (Pflüger's Archiv, vi, 175) that 10,000 electric

shocks a second are felt as interrupted, by the tongue (!). Von Wittich

(_ibid._ ii, 329), that between 1000 and 2000 strokes a second are

felt as discrete by the finger. W. Preyer, on the other hand (Die

Grenzen des Empfindungsvermögens, etc., 1868, p. 15), makes contacts

appear continuous to the finger when 36.8 of them follow in a second.

Similarly, Mach (Wiener Sitzgsb., li, 2, 142) gives about 26. Lalanne

(Comptes Rendus, i/xxxii, p. 1314) found summation of finger contacts

after 22 repetitions in a second. Such discrepant figures are of

doubtful worth. On the retina 20 to 30 impressions a second at the

very utmost can be felt as discrete when they fail on the same spot.

The ear, which begins to fuse stimuli together into a musical tone

when they follow at the rate of a little over 30 a second, can still

feel 132 of them a second as discontinuous when they take the shape of

'beats' (Helmholtz, Tonempfindungen, 3d ed. p. 270).

[526] Pflüger's Archiv, xi, 428. Also in Herrmann's Hdbh. d. Physiol.,

2 Bd. i, Thl. pp. 260-2.

[527] Pflüger's Archiv, vii, 639. Tigerstedt (Bihang till Kongl.

Svenska Vetenskaps Akad, Handl., Bd. 8, Häfte 2, Stockholm, 1884)

revises Exner's figures, and shows that his conclusions are

exaggerated. According to Tigerstedt, two observers almost always

rightly appreciated 0.05 or 0.06'' of reaction-time difference. Half

the time they did it rightly when the difference sank to 0.03'', though

from 0.03'' and 0.06'' differences were often not noticed at all.

Buccola found (La Legge del Tempo nei Fenomeni dei Pensiero, Milano,

1883, p. 371) that, after much practice in making rapid reactions upon

a signal, he estimated directly, in figures, his own reaction-time, in

10 experiments, with an error of from 0.016'' to 0.018''; in 6, with

one of 0.005'' to 0.069''; in one, with one of 0.002''; and in 3, with

one of 0.003''.

[528] Mind, xi, 61 (1886).

[529] Mach, Wiener Sitzungsb., li, 2. 133 (1865); Estel, _loc. cit._

p. 65; Mehner, _loc. cit._ p. 586; Buccola, _op. cit._ p. 378. Fechner

labors to prove that his law is only overlaid by other interfering laws

in the figures recorded by these experimenters; but his case seems

to me to be one of desperate infatuation with a hobby. (See Wundt's

Philosphische Studien iii, 1.)

[530] Curious discrepancies exist between the German and the American

observers with respect to the _direction_ of the error below and above

the point of indifference--differences perhaps due the _fatigue_

involved in the American method. The Germans lengthened intervals below

it and shortened those above. With seven Americans experimented on by

Stevens this was exactly reversed. The German method was to passively

listen to the intervals, then judge; the American was to reproduce

them actively by movements of the hand. In Mehner's experiments there

was found a second indifference point at about 5 seconds, beyond which

times were judged again too long. Glass, whose work on the subject is

the latest (Philos. Studien, iv, 423) found (when corrections were

allowed for) that all times except 0.8 sec. were estimated too short.

He found a series of points of greatest relative accuracy, viz. at

1.5, 2.5, 3.75, 5, 6.25, etc., seconds respectively, and thought that

his observations roughly corroborated Weber's law. As 'maximum' and

'minimum' are printed interchangeably in Glass's article it is hard to

follow.

[531] With Vierordt and his pupils the indifference point lay as

high as from 1.5 sec to 4.9 sec, according to the observer (cf. Der

Zeitsinn, 1868, p. 112). In most of these experiments the time heard

was actively reproduced, after a short pause, by movements of the hand,

which were recorded. Wundt gives good reasons (Physiol. Psych., ii,

289, 290) for rejecting Vierordt's figures as erroneous. Vierordt's

book, it should be said, is full of important matter, nevertheless.

[532] Physiol. Psych., ii, 286, 290.

[533] Philosophische Studien, i, 86.

[534] Mind, xi, 400.

[535] _Loc cit._ p. 144.

[536] _Op. cit._ p. 376. Mach's and Buccola's figures, it will be

observed, are about _one half_ of the rest--sub-multiples, therefore.

It ought to be observed, however, that Buccola's figure has little

value, his observations not being well fitted to show this particular

point.

[537] Estel's figures led him to think that _all_ the multiples

enjoyed this privilege; with Mehner, on the other hand, only the _odd_

multiples showed diminution of the average error; thus, 0.71, 2.15,

3.55, 5, 6.4, 7.8, 9.3, and 10.65 second were respectively registered

with the least error. Cf. Phil. Studien, ii, pp. 57, 562-5.

[538] Cf. especially pp. 558-561.

[539] Wundt: Physiol. Psych., ii, 287. Hall and Jastrow: Mind, xi, 62.

[540] Mehner: _loc. cit._ p. 553.

[541] The number of distinguishable _differences_ of speed between

these limits is, as he takes care to remark, very much larger that 7.

(Der Zeitsinn, p. 137).

[542] P. 19, § 18, p. 112.

[543] I leave the text just as it was printed in the Journal of

Speculative Philosophy (for 'Oct. 1886') in 1887. Since then

Münsterberg in his masterly Beiträge zur experimentellen Psychologie

(Heft 2, 1889) seems to have made it clear what the sensible changes

are by which we measure the lapse of time. When the time which

separates two sensible impressions is less than one third of a second,

he thinks it is almost entirely the amount to which the memory-image

of the first impression has faded when the second one overtakes

it, which makes us feel how wide they are apart (p. 29). When the

time is longer than this, we rely, he thinks, exclusively upon the

feelings of muscular tension and relaxation, which we are constantly

receiving although we give to them so little of our direct attention.

These feelings are primarily in the muscles by which we adopt our

sense-organs in attending to the signals used, some of the muscles

being in the eye and ear themselves, some of them in the head, neck,

etc. We here judge two time-intervals to be equal when between the

beginning and end of each we feel exactly similar relaxations and

subsequent expectant tensions of these muscles to have occurred. In

reproducing intervals ourselves we try to make our feelings of this

sort just what they were when we passively heard the interval. These

feelings by themselves, however, can only be used when the intervals

are very short, for the tension anticipatory of the terminal stimulus

naturally reaches its maximum very soon. With longer intervals we _take

the feeling of our inspirations and expirations into account_. With

our expirations all the other muscular tensions in our body undergo a

rhythmical decrease; with our inspirations the reverse takes place.

When, therefore, we note a time-interval of several seconds with

intent to reproduce it, what we seek is to make the earlier and later

interval agree in the number and amount of these respiratory changes

combined with sense-organ adjustments with which they are filled.

Münsterberg has studied carefully in his own ease the variations of

the respiratory factor. They are many; but he sums up his experience

by saying that whether he measured by inspirations that were divided

by momentary pauses into six parts, or by inspirations that were

continuous; whether with sensory tension during inspiration and

relaxation during expiration, or by tension during both inspiration

and expiration, separated by a sudden interpolated relaxation; whether

with special notice taken of the cephalic tensions, or of those in

the trunk and shoulders, in all cases alike and without exception he

involuntarily endeavored, whenever he compared two times or tried to

make one the same as the other, to get exactly the same respiratory

conditions and conditions of tension, _all_ the subjective conditions,

in short, _exactly_ the same during the second interval as they were

during the first. Münsterberg corroborated his subjective observations

by experiments. The observer of the time had to reproduce as exactly

as possible an interval between two sharp sounds given him by an

assistant. The only condition imposed upon him was that he should not

modify his breathing for the purposes of measurement. It was then

found that when the assistant broke in at random with his signals,

the judgment of the observer was vastly less accurate than when the

assistant carefully watched the observer's breathing and made both

the beginning of the time given him and that of the time which he was

to give coincide with identical phases thereof.--Finally, Münsterberg

with great plausibility tries to explain the discrepancies between the

results of Vierordt, Estel, Mehner, Glass, etc., as due to the fact

that they _did not all use the same measure_. Some breathe a little

faster, some a little slower. Some break their inspirations into

two parts, some do not, etc. The coincidence of the objective times

measured with definite natural phases of breathing would very easily

give periodical maxima of facility in measuring accurately.

[544] "Any one wishing yet further examples of this mental substitution

will find one on observing how habitually he thinks of the spaces

on the clock-face instead of the periods they stand for; how, on

discovering it to be half an hour later than be supposed, he does not

represent the half hour in its duration, but scarcely passes beyond the

sign of it marked by the finger." (H. Spencer: Psychology, § 336.)

[545] The only objections to this which I can think of are: (1)

The accuracy with which some men judge of the hour of day or night

without looking at the clock; (2) the faculty some have of waking at

a preappointed hour; (3) the accuracy of time-perception reported to

exist in certain trance-subjects. It might seem that in these persons

some sort of a sub-conscious record was kept of the lapse of time

_per se_. But this cannot be admitted until it is proved that there

are no physiological processes, the feeling of whose course may serve

as a _sign_ of how much time has sped, and so lead us to infer the

hour. That there are such processes it is hardly possible to doubt. An

ingenious friend of mine was long puzzled to know why each day of the

week had such a characteristic physiognomy to him. That of Sunday was

soon noticed to be due to the cessation of the city's rumbling, and

the sound of people's feet shuffling on the sidewalk; of Monday, to

come from the clothes drying in the yard and casting a white reflection

on the ceiling; of Tuesday, to a cause which I forget; and I think my

friend did not get beyond Wednesday. Probably each hour in the day has

for most of us some outer or inner sign associated with it as closely

as these signs with the days of the week. It must be admitted, after

all, however, that the great improvement of the time-perception during

sleep and trance is a mystery not as yet cleared up. All my life I have

been struck by the accuracy with which I will wake at the same exact

minute night after night and morning after morning, if only the habit

fortuitously begins. The organic registration in me is independent of

sleep. After lying in bed a long time awake I suddenly rise without

knowing the time, and for days and weeks together will do so at an

identical minute by the clock, as if some inward physiological process

caused the act by punctually running down.-—Idiots are said sometimes

to possess the time-measuring faculty in a marked degree. I have an

interesting manuscript account of an idiot girl which says: "She was

punctual almost to a minute in her demand for food and other regular

attentions. Her dinner was generally furnished her at 12.30 p. m., and

at that hour she would begin to scream if it were not forthcoming. If

on Fast-day or Thanksgiving it were delayed, in accordance with the

New England custom, she screamed from her usual dinner-hour until the

food was carried to her. On the next day, however, she again made known

her wants promptly at 12.30. Any slight attention shown her on one

day was demanded on the next at the corresponding hour. If an orange

were given her at 4 p. m. on Wednesday, at the same hour on Thursday

she made known her expectation, and if the fruit were not given her

she continued to call for it at intervals for two or three hours. At

four on Friday the process would be repeated but would last less long;

and so on for two or three days. If one of her sisters visited her

accidentally at a certain hour, the sharp piercing scream was sure

to summon her at the same hour the next day," etc., etc.--For these

obscure matters consult C. Du Prel: The Philosophy of Mysticism, chap.

iii, § 1.

[546] Ideale Fragen (1878). p. 219 (Essay, 'Zeit und Weile').

[547] Revue Philosophique, vol. iii, p. 496.

[548] "Empty time is most strongly perceived when it comes as a _pause_

in music or in speech. Suppose a preacher in the pulpit, a professor

at his desk, to stick still in the midst of his discourse; or let a

composer (as is sometimes purposely done) make all his instruments stop

at once; we await every instant the resumption of the performance,

and, in this awaiting, perceive, more than in any other possible way,

the empty time. To change the example, let, in a piece of polyphonic

music--a figure, for instance, in which a tangle of melodies are

under way--suddenly a single voice be heard, which sustains a long

note, while all else is hushed.... This one note will appear very

protracted--why? Because we _expect_ to hear accompanying it the notes

of the other instruments, but they fail to come." (Herbart: Psychol.

als W., § 115.)--Compare also Münsterberg, Beiträge, Heft 2, p. 41.

[549] A night of pain will seem terribly long: we keep looking forward

to a moment which never comes--the moment when it shall cease. But the

odiousness of this experience is not named _ennui_ or _Langweile_, like

the odiousness of time that seems long from its emptiness. The more

positive odiousness of the pain, rather, is what tinges our memory of

the night. What we feel, as Prof. Lazarus says (_op. cit._ p. 202), is

the long time of the suffering, not the suffering of the long time _per

se_.

[550] On these variations of time-estimate, cf. Romanes, Consciousness

of Time, in Mind, vol. iii, p. 297; J. Sully, Illusions, pp. 245-261,

302-305; W. Wundt. Physiol. Psych., ii, 287, 288; besides the essays

quoted from Lazarus and Janet. In German, the successors of Herbart

have treated of this subject: compare Volkmann's Lehrbuch d. Psych.,

§ 89, and for references to other authors his note 3 to this section.

Lindner (Lbh. d. empir. Psych.), as a parallel effect, instances

Alexander the Great's life (thirty-three years), which seems to us as

if it must be long, because it was so eventful. Similarly the English

Commonwealth, etc.

[551] Physiol. Optik, p. 445.

[552] Succession, time _per se_, is no force. Our talk about its

devouring tooth, etc., is all elliptical. Its contents are what devour.

The law of inertia is incompatible with time's being assumed as an

efficient cause of anything.

[553] Lehrbuch d. Psych., § 87. Compare also H. Lotze, Metaphysik, §

154.

[554] The cause of the perceiving, not the object perceived!

[555] "'No more' and 'not yet' are the proper time-feelings, and we

are aware of time in no other way than through these feelings," says

Volkmann (Psychol., § 87). This, which is not strictly true of our

feeling of _time per se_, as an elementary bit of duration, is true of

our feeling of _date_ in its events.

[556] We construct the miles just as we construct the years. Travelling

in the cars makes a succession of different fields of view pass before

our eyes. When those that have passed from present sight revive in

memory, they maintain their mutual order because their contents

overlap. We think them as having been before or behind each other;

and, from the multitude of the views we can recall behind the one now

presented, we compute the total space we have passed through.

It is often said that the perception of time develops later than

that of space, because children have so vague an idea of all dates

before yesterday and after to-morrow. But no vaguer than they have

of extensions that exceed as greatly their unit of space-intuition.

Recently I heard my child of four tell a visitor that he had been 'as

much as one week' in the country. As he had been there three months,

the visitor expressed surprise; whereupon the child corrected himself

by saying he had been there 'twelve years.' But the child made exactly

the same kind of mistake when he asked if Boston was not one hundred

miles from Cambridge, the distance being three miles.

[557] Most of these explanations simply give the _signs_ which,

adhering to impressions, lead us to date them within a duration, or,

in other words, to assign to them their order. Why it should be a

_time_-order, however, is not explained. Herbart's would-be explanation

is a simple description of time-perception. He says it comes when,

with the last member of a series present to our consciousness, we also

think of the first; and then the whole series revives in our thought

at once, but with strength diminishing in the backward direction

(Psychol. als Wiss., § 115; Lehrb. zur Psychol., §§ 171, 172, 175).

Similarly Drobisch, who adds that the series must appear as one already

_elapsed_ (_durchlaufene_), a word which shows even more clearly

the question-begging nature of this sort of account (Empirische

Psychol., § 59). Th. Waitz is guilty of similar question-begging

when he explains our time-consciousness to be engendered by a

set of unsuccessful attempts to make our percepts agree with our

_expectations_ (Lehrb. d. Psychol., § 52). Volkmann's mythological

account of past representations striving to drive present ones out

of the seat of consciousness, being driven _back_ by them, etc.,

suffers from the same fallacy (Psychol., § 87). But all such accounts

agree in implying one fact—-viz., that the brain-processes of various

events must be active simultaneously, and in varying strength, for

a time-perception to be possible. Later authors have made this idea

more precise. Thus, Lipps: "Sensations arise, occupy consciousness,

fade into images, and vanish. According as two of them, _a_ and _b_,

go through this process simultaneously, or as one precedes or follows

the other, the _phases of their fading_ will agree or differ; and the

difference will be proportional to the time-difference between their

several moments of beginning. Thus there are differences of _quality_

in the images, which the mind may _translate_ into corresponding

differences of their temporal order. There is no other possible middle

term between the objective time-relations and those in the mind than

these differences of phase." (Grundtatsachen des Seelenlebens, p. 588.)

Lipps accordingly calls them 'temporal signs,' and hastens explicitly

to add that the soul's translation of their order of strength into a

time-order is entirely inexplicable (p. 591). M. Guyau's account (Revue

Philosophique, xix, 353) hardly differs from that of his predecessors,

except in picturesqueness of style. Every change leaves a series of

_trainées lumineuses_ in the mind like the passage of shooting stars.

Each image is in a more fading phase, according as its original was

more remote. This group of images gives duration, the mere time-form,

the 'bed' of time. The distinction of past, present, and future within

the bed comes from our active nature. The future (as with Waitz) is

what I want, but have not yet got, and must wait for. All this is

doubtless true, but is no _explanation_.

Mr. Ward gives, in his Encyclopædia Britannica article (Psychology,

p. 65, col. 1), a still more refined attempt to specify the 'temporal

sign.' The problem being, among a number of other things thought as

successive, but simultaneously thought, to determine which is first and

which last, he says: "After each distinct representation, _a b c d,_

there may intervene the representation of that _movement of attention_

of which we are aware in passing from one object to another. In our

present reminiscence we have, it must be allowed, little direct proof

of this intervention; though there is, I think, indirect evidence of

it in the tendency of the flow of ideas to follow the order in which

the presentations were at first attended to. With the movement itself

when the direction of attention changes, we are familiar enough, though

the residua of such movements are not ordinarily conspicuous. These

residua, then, are our temporal signs.... But temporal signs alone

will not furnish all the pictorial exactness of the time-perspective.

These give us only a fixed series; but the law of obliviscence, by

insuring a progressive variation in intensity as we pass from one

member of the series to the other, yields the effect which we call

time-distance. By themselves such variations in intensity would leave

us liable to confound more vivid representations in the distance with

fainter ones nearer the present, but from this mistake the temporal

signs save us; where the memory-continuum is imperfect such mistakes

continually occur. On the other hand, where these variations are

slight and imperceptible, though the memory-continuum preserves the

order of events intact, we have still no such distinct appreciation of

comparative distance in time as we have nearer to the present, where

these perceptive effects are considerable.... Locke speaks of our ideas

succeeding each other 'at certain distances not much unlike the images

in the inside of a lantern turned round by the heat of a candle,' and

'guesses' that 'this appearance of theirs in train varies not very

much in a waking man.' _Now what is this 'distance' that separates a

from b, b from c, and so on;_ and what means have we of knowing that

it is tolerably constant in waking life? _It is, probably, that, the

residuum of which I have called a temporal sign; or, in other words,

it is the movement of attention from a to b._" Nevertheless, Mr. Ward

does not call our feeling of this movement of attention the _original_

of our feeling of time, or its brain-process the brain-process which

directly causes us to perceive time. He says, a moment later, that

"though the fixation of attention does of course really occupy time,

it is probably not in the first instance perceived as time--i.e. as

continuous 'protensity,' to use a term of Hamilton's--but as intensity.

Thus, if this supposition be true, there is an element in our concrete

time perceptions which has no place in our abstract conception of

Time. In Time physically conceived there is no trace of intensity;

in time psychically experienced, duration is primarily an intensive

magnitude, and so far literally a perception." Its 'original' is, then,

if I understand Mr Ward, something like a _feeling_ which accompanies,

as pleasure and pain may accompany, the movements of attention. Its

brain-process must, it would seem, be assimilated in general type to

the brain-processes of pleasure and pain. Such would seem more or

less consciously to be Mr. Ward's own view, for he says: "Everybody

knows what it is to be distracted by a rapid succession of varied

impressions, and equally what it is to be wearied by the slow and

monotonous recurrence of the same impressions. Now these 'feelings'

of distraction and tedium owe their characteristic qualities to

movements of attention. In the first, attention is kept incessantly

on the move; before it is accommodated to _a_, it is disturbed by

the suddenness, intensity, and novelty of _b_; in the second, it is

kept all but stationary by the repeated presentation of the same

impression. Such excess and defect of surprises make one realize a fact

which in ordinary life is so obscure as to escape notice. But recent

experiments have set this fact in a more striking light, and made clear

what Locke had dimly before his mind in talking of a certain distance

between the presentations of a waking man. In estimating very short

periods of time of a second or less, indicated, say, by the beats of

a metronome, it is found that there is a certain period for which the

mean of a number of estimates is correct, while shorter periods are on

the whole over-, and longer periods under-estimated. I take this to be

evidence of the time occupied in accommodating or fixing attention."

Alluding to the fact that a series of experiences, _a b c d e,_ may

seem short in retrospect, which seemed everlasting in passing, he

says: "What tells in retrospect is the series _a b c d e_, etc.; what

tells in the present is the intervening _t_{1} t_{2} t_{3},_ etc., or

rather the original accommodation of which these temporal signs are

the residuum." And he concludes thus: "We seem to have proof that our

perception of duration rests ultimately upon quasi-motor objects of

varying intensity, the duration of which we do not directly experience

as duration at all."

Wundt also thinks that the interval of about three-fourths of a second,

which is estimated with the minimum of error, points to a connection

between the time-feeling and the succession of distinctly 'apperceived'

objects before the mind. The 'association-time' is also equal to about

three fourths of a second. This association-time he regards as a sort

of internal standard of duration to which we involuntarily assimilate

all intervals which we try to reproduce, bringing shorter ones up to

it and longer ones down. [In the Stevens result we should have to say

_contrast_ instead of assimilate, for the longer intervals there seem

longer, and the shorter ones shorter still.] "Singularly enough," he

adds (Physiol. Psych., ii, 286), "this time is about that in which in

rapid walking, according to the Webers, our legs perform their swing.

It seems thus not unlikely that both psychical constants, that of the

average speed of reproduction and that of the surest estimation of

time, have formed themselves under the influence of those most habitual

movements of the body which we also use when we try to subdivide

rhythmically longer tracts of time."

Finally, Prof. Mach makes a suggestion more specific still. After

saying very rightly that we have a real _sensation_ of time--how

otherwise should we identify two entirely different airs as being

played in the same 'time'? how distinguish in memory the first stroke

of the clock from the second, unless to each there clove its special

time-sensation, which revived with it?--he says "it is probable that

this feeling is connected with that organic _consumption_ which is

necessarily linked with the production of consciousness, and that the

time which we feel is probably due to the [mechanical?] _work of_

[the process of?] _attention_. When attention is strained, time seems

long; during easy occupation, short, etc.... The fatigue of the organ

of consciousness, as long as we wake, continually increases, and the

work of attention augments as continually. Those impressions which

are conjoined with a _greater amount_ of work of attention appear to

us as the _later_." The apparent relative displacement of certain

simultaneous events and certain anachronisms of dreams are held by Mach

to be easily explicable as effects of a splitting of the attention

between two objects, one of which consumes most of it (Beiträge zur

Analyse der Empfindungen, p. 103 foll.). Mach's theory seems worthy of

being better worked out. It is hard to say now whether he, Ward, and

Wundt mean at bottom the same thing or not. The theory advanced in my

own text, it will be remarked, does not pretend to be an _explanation_,

but only an elementary statement of the 'law' which makes us aware of

time. The Herbartian mythology purports to _explain_.

[558] It would be rash to say definitely just how many seconds

long this specious present must needs be, for processes fade

'asymptotically,' and the distinctly intuited present merges into a

penumbra of mere dim _recency_ before it turns into the past which

is simply reproduced and conceived. Many a thing which we do not

distinctly date by intercalating it in a place between two other things

will, nevertheless, come to us with this feeling of belonging to a

_near_ past. This sense of recency is a feeling _sui generis_, and

may affect things that happened hours ago. It would seem to show that

their brain-processes are still in a state modified by the foregoing

excitement, still in a 'fading' phase, in spite of the long interval.

[559] Physiol. Psych, ii, 263.

[560] I leave my text as it was printed before Münsterberg's essay

appeared (see Footnote 542, above). He denies that we measure any but

minimal durations by the amount of fading in the ideational processes,

and talks almost exclusively of our feelings of muscular tension in

his account, whereas I have made no mention of such things in mine. I

cannot, however, see that there is any conflict between what he and

I suggest. I am mainly concerned with the consciousness of duration

regarded as a specific sort of object, he is concerned with this

object's measurement exclusively. Feelings of tension might be the

means of the measurement, whilst overlapping processes of any and every

kind gave the object to be measured. The accommodative and respiratory

movements from which the feelings of tension come form regularly

recurring sensations divided by their 'phases' into intervals as

definite as those by which a yardstick is divided by the marks upon its

length.

Let _a^1, a^2, a^3, a^4,_ be homologous phases in four successive

movements of this kind. If four outer stimuli 1, 2, 3, 4, coincide

each with one of these successive phases, then their 'distances apart'

are felt as _equal_, otherwise not. But there is no reason whatever

to suppose that the mere overlapping of the brain-process of 2 by the

fading process of 1, or that of 3 by that of 2, etc., does not give

the _characteristic quality of content_ which we call 'distance apart'

in this experience, and which by aid of the muscular feelings gets

judged to be equal. Doubtless the muscular feelings can give us the

object 'time' as well as its measure, because their earlier phases

leave fading sensations which constantly overlap the vivid sensation of

the present phase. But it would be contrary to analogy to suppose that

they should be the only experiences which give this object. I do not

understand Herr Münsterberg to claim this for them. He takes our sense

of time for granted, and only discusses its measurement.

[561] Exner in Hermann's Hdbch. d. Physiol., Bd. ii, Thl. ii, p. 281.

Richet in Revue Philosophique, xxi, 568 (juin, 1886). See the next

chapter, pp. 642-646.

[562] I have spoken of _fading_ brain-processes alone, but only for

simplicity's sake. _Dawning_ processes probably play as important a

part in giving the feeling of duration to the specious present.

[563] Reden (St. Petersburg, 1864), vol. i, pp. 255-268.

[564] Psychology, § 91.

[565] "The patient cannot retain the image of an object more than

a moment. His memory is as short for sounds, letters, figures, and

printed words. If we cover a written or printed word with a sheet of

paper in which a little window has been cut, so that only the first

letter is visible through the window, he pronounces this letter. If,

then, the sheet is moved so as to cover the first letter and make the

second one visible, he pronounces the second, but forgets the first,

and cannot pronounce the first and second together." And so forth to

the end. "If he closes his eyes and draws his finger exploringly over a

well-known object like a knife or key, he cannot combine the separate

impressions and recognize the object. But if it is put into his hand

so that he can simultaneously touch it with several fingers, he names

it without difficulty. This patient has thus lost the capacity for

grouping successive ... impressions ... into a whole and perceiving

them as a whole." (Grashey, in Archiv für Psychiatrie, Bd. xvi, pp.

672-673.) It is hard to believe that in such a patient the time

intuited was not clipped off like the impressions it held, though

perhaps not so much of it.

I have myself often noted a curious exaggeration of time-perspective

at the moment of a falling asleep. A person will be moving or doing

something in the room, and a certain stage of his act (whatever it may

be) will be my last waking perception. Then a subsequent stage will

wake me to a new perception. The two stages of the act will not be more

than a few seconds apart; and yet it always seems to me as if, between

the earlier and the later one, a long interval has passed away. I

conjecturally account for the phenomenon thus, calling the two stages

of the act _a_ and _b_ respectively: Were I awake, _a_ would leave a

fading process in my sensorium which would overlap the process of _b_

when the latter came, and both would then appear in the same specious

present, _a_ belonging to its earlier end. But the sudden advent of the

brain-change called sleep extinguishes _a_'s fading process abruptly.

When _b_ then comes and wakes me, _a_ comes back, it is true, but not

as belonging to the specious present. It has to be specially _revoked_

in memory. This mode of revocation usually characterizes long-past

things--whence the illusion.

[566] Again I omit the future, merely for simplicity's sake.

CHAPTER XVI.

MEMORY.

In the last chapter what concerned us was the direct _intuition_ of

time. We found it limited to intervals of considerably less than a

minute. Beyond its borders extends the immense region of _conceived_

time, past and future, into one direction or another of which we

mentally project all the events which we think of as real, and form

a systematic order of them by giving to each a date. The relation of

conceived to intuited time is just like that of the fictitious space

pictured on the flat back-scene of a theatre to the actual space of the

stage. The objects painted on the former (trees, columns, houses in a

receding street, etc.) carry back the series of similar objects solidly

placed upon the latter, and we think we see things in a continuous

perspective, when we really see thus only a few of them and imagine

that we see the rest. The chapter which lies before us deals with the

way in which we paint the remote past, as it were, upon a canvas in our

memory, and yet often imagine that we have direct vision of its depths.

The stream of thought flows on; but most of its segments fall into the

bottomless abyss of oblivion. Of some, no memory survives the instant

of their passage. Of others, it is confined to a few moments, hours,

or days. Others, again, leave vestiges which are indestructible, and

by means of which they may be recalled as long as life endures. Can we

explain these differences?

PRIMARY MEMORY.

The first point to be noticed is that _for a state of mind to survive

in memory it must have endured, for a certain length of time_. In

other words, it must be what I call a substantive state. Prepositional

and conjunctival states of mind are not remembered as independent

facts--we cannot recall just how we felt when we said 'how' or

'notwithstanding.' Our consciousness of these transitive states is

shut up to their own moment--hence one difficulty in introspective

psychologizing.