RESULTS.
The foregoing study of illusions may not improbably have had a
bewildering effect on the mind of the reader. To keep the mental eye,
like the bodily eye, for any time intently fixed on one object is apt to
produce a feeling of giddiness. And in the case of a subject like
illusion, the effect is enormously increased by the disturbing character
of the object looked at. Indeed, the first feeling produced by our
survey of the wide field of illusory error might be expressed pretty
accurately by the despondent cry of the poet--
"Alas! it is delusion all:
The future cheats us from afar,
Nor can we be what we recall,
Nor dare we think on what we are."
It must be confessed that our study has tended to bring home to the mind
the wide range of the illusory and unreal in our intellectual life. In
sense-perception, in the introspection of the mind's own feelings, in
the reading of others' feelings, in memory, and finally in belief, we
have found a large field for illusory cognition. And while illusion has
thus so great a depth in the individual mind, it has a no less striking
breadth or extent in the collective human mind. No doubt its grosser
forms manifest themselves most conspicuously in the undisciplined mind
of the savage and the rustic; yet even the cultivated mind is by no
means free from its control. In truth, most of the illusions illustrated
in this work are such as can be shared in by all classes of mind.
In view of this wide far-reaching area of ascertained error, the mind
naturally asks, What are the real limits of illusory cognition, and how
can we be ever sure of having got beyond them? This question leads us on
to philosophical problems of the greatest consequence, problems which
can only be very lightly touched in this place. Before approaching
these, let us look back a little more carefully and gather up our
results, reflect on the method which we have been unconsciously
adopting, and inquire how far this scientific mode of procedure will
take us in determining what is the whole range of illusory cognition.
We have found an ingredient of illusion mixed up with all the popularly
recognized forms of immediate knowledge. Yet this ingredient is not
equally conspicuous in all cases. First of all, illusion varies very
considerably in its degree of force and persistence. Thus, in general, a
presentative illusion is more coercive than a representative; an
apparent reality present to the mind is naturally felt to be more
indubitable than one absent and only represented. On the other hand, a
representative illusion is often more enduring than a presentative, that
is to say, less easily found out. It is to be added that a good deal of
illusion is only partial, there being throughout an under-current of
rational consciousness, a gentle play of self-criticism, which keeps the
error from developing into a perfect self-delusion. This remark applies
not only to the innocent illusions of art, but also to many of our
every-day illusions, both presentative and representative. In many
cases, indeed, as, for example, in looking at a reflection in a mirror,
the illusion is very imperfect, remaining in the nascent stage.
Again, a little attention to the facts here brought together will show
that the proportion of illusory to real knowledge is far from being the
same in each class of immediate or quasi-immediate cognition. Thus, with
respect to the great distinction between presentative and representative
knowledge, it is to be observed that, in so far as any act of cognition
is, strictly speaking, presentative, it does not appear to admit of
error. The illusions of perception are connected with the representative
side of the process, and are numerous just because this is so extensive.
On the other hand, in introspection, where the scope of independent
representation is so limited, the amount of illusion is very
inconsiderable, and may in practice be disregarded. So again, to take a
narrower group of illusions, we find that in the recalling of distant
events the proportion of error is vastly greater than in the recalling
of near events.
So much as to the extent of illusion as brought to light by our
preceding study. Let us now glance at the conclusions obtained
respecting its nature and its causes.
_Causes of Illusion._
Looking at illusion as a whole, and abstracting from the differences of
mental mechanism in the processes of perception, memory, etc., we may
say that the _rationale_ or mode of genesis of illusion is very much the
same throughout. Speaking broadly, one may describe all knowledge as a
correspondence of representation with fact or experience, or as a stable
condition of the representation which cannot be disturbed by new
experiences. It does not matter, for our present purpose, whether the
fact represented is supposed to be directly present, as in presentative
cognition; or to be absent, either as something past or future, or
finally as a "general fact," that is to say, the group of facts (past
and future) embodied in a universal proposition.[147]
In general this accordance between our representations and facts is
secured by the laws of our intellectual mechanism. It follows from the
principles of association that our simple experiences, external and
internal, will tend to reflect themselves in perception, memory,
expectation, and general belief, in the very time-connections in which
they actually occur. To put it briefly, facts which occur together will
in general be represented together, and they will be the more perfectly
co-represented in proportion to the frequency of this concurrence.
Illusion, as distinguished from correct knowledge, is, to put it
broadly, deviation of representation from fact. This is due in part to
limitations and defects in the intellectual mechanism itself, such as
the imperfections of the activities of attention, discrimination, and
comparison, in relation to what is present. Still more is it due to the
control of our mental processes by association and habit. These forces,
which are at the very root of intelligence, are also, in a sense, the
originators of error. Through the accidents of our experience or the
momentary condition of our reproductive power, representations get
wrongly grouped with presentations and with one another; wrongly
grouped, that is to say, according to a perfect or ideal standard,
namely, that the grouping should always exactly agree with the order of
experience as a whole, and the force of cohesion be proportionate to the
number of the conjunctions of this experience.
This great source of error has been so abundantly illustrated under the
head of Passive Illusions that I need not dwell on it further. It is
plain that a passive error of perception, or of expectation, is due in
general to a defective grouping of elements, to a grouping which
answers, perhaps, to the run of the individual's actual experience, but
not to a large and complete common experience.[148] Similarly, an
illusory general belief is plainly a welding together of elements (here
concepts, answering to innumerable representative images) in
disagreement with the permanent connections of experience. Even a
passive illusion of memory, in so far as it involves a rearrangement of
successive representations, shows the same kind of defect.
In the second place, this incorrect grouping maybe due, not to defects
in attention and discrimination, combined with insufficiently grounded
association, but to the independent play of constructive imagination and
the caprices of feeling. This is illustrated in what I have called
Active Illusions, whether the excited perceptions and the hallucinations
of sense, or the fanciful projections of memory or of expectation. Here
we have a force directly opposed to that of experience. Active illusion
arises, not through the imperfections of the intellectual mechanism, but
through a palpable interference with this mechanism. It is a regrouping
of elements which simulates the form of a suggestion by experience, but
is, in reality, the outcome of the individual mind's extra-intellectual
impulses.
We see, then, that, in spite of obvious differences in the form, the
process in all kinds of immediate cognition is fundamentally identical.
It is essentially a bringing together of elements, whether similar or
dissimilar and associated by a link of contiguity, and a viewing of
these as connected parts, of a whole; it is a process of synthesis. And
illusion, in all its forms, is bad grouping or carelessly performed
synthesis. This holds good even of the simplest kinds of error in which
a presentative element is wrongly classed; and it holds good of those
more conspicuous errors of perception, memory, expectation, and compound
belief, in which representations connect themselves in an order not
perfectly answering to the objective order.
This view of the nature and causes of illusion is clearly capable of
being expressed in physical language. Bad grouping of psychical elements
is equivalent to imperfect co-ordination of their physical, that is to
say, nervous, conditions, imperfect in the evolutionist's sense, as not
exactly according with external relations. So far as illusions of
suggestion (passive illusions) are concerned, the error is connected
with organized tendencies, due to a limited action of experience. On the
other hand, illusions of preconception (active illusions) usually
involve no such deeply fixed or permanent organic connections, but
merely a temporary confluence of nerve-processes.[149] The nature of the
physical process is best studied in the case of errors of
sense-perception. Yet we may hypothetically argue that even in the case
of the most complex errors, as those of memory and of belief, there is
implied a deviation in the mode of connection of nervous structures
(whether the connection be permanent or temporary) from the external
order of facts.
And now we are in a position to see whether illusion is ultimately
distinguishable from other modes of error, namely, those incident to
conscious processes of reasoning. It must have been plain to an
attentive reader throughout our exposition that, in spite of our
provisional distinction, no sharp line can be drawn between much of
what, on the surface, looks like immediate knowledge, and consciously
derived or inferred knowledge. On its objective side, reasoning may be
roughly defined as a conscious transition of mind from certain facts or
relations of facts to other facts or relations recognized as similar.
According to this definition, a fallacy would be a hasty, unwarranted
transition to new cases not identical with the old. And a good part of
immediate knowledge is fundamentally the same, only that here, through
the exceptional force of association and habit, the transition is too
rapid to be consciously recognized. Consequently, illusion becomes
identified at bottom with fallacious inference: it may be briefly
described as collapsed inference. Thus, illusory perception and
expectation are plainly a hasty transition of mind from old to new, from
past to present, conjunctions of experience.[150] And, as we have seen,
an illusory general belief owes its existence to a coalescence of
representations of known facts or connections with products of
imagination which simulate the appearance of inferences from these
facts.
In the case of memory, in so far as it is not aided by reasoning from
present signs, there seems to be nothing like a movement of inference.
It is evident, indeed, that memory is involved in and underlies every
such transition of thought. Illusions of memory illustrate rather a
process of wrong classing, that is to say, of wrongly identifying the
present mental image with past fact, which is the initial step in all
inference. In this way they closely resemble those slight errors of
perception which are due to erroneous classing of sense-impressions. But
since the intellectual process involved in assimilating mental elements
is very similar to that implied in assimilating complex groups of such
elements, we may say that even in these simple kinds of error there is
something which resembles a wrong classing of relations, something,
therefore, which approximates in character to a fallacy.
By help of this brief review of the nature and causes of illusion, we
see that in general it may be spoken of as deviation of individual from
common experience. This applies to passive illusion in so far as it
follows from the accidents of individual experience, and it still more
obviously applies to active illusion as due to the vagaries of
individual feeling and constructive imagination. We might, perhaps,
characterize all illusion as partial view, partial both in the sense of
being incomplete, and in the other sense of being that to which the mind
by its peculiar predispositions inclines. This being so, we may very
roughly describe all illusion as abnormal. Just as hallucination, the
most signal instance of illusion, is distinctly on the border-land of
healthy and unhealthy mental life; just as dreams are in the direction
of such unhealthy mental action; so the lesser illusions of memory and
so on are abnormal in the sense that they imply a departure from a
common typical mode of intellectual action.
It is plain, indeed, that this is the position we have been, taking up
throughout our discussion of illusion. We have assumed that what is
common and normal is true, or answers to what is objectively real. Thus,
in dealing with errors of perception, we took for granted that the
common percept--meaning by this what is permanent in the individual and
the general experience--is at the same time the true percept. So in
discussing the illusions of memory we estimated objective time by the
judgment of the average man, free from individual bias, and apart from
special circumstances favourable to error. Similarly, in the case of
belief, true belief was held to be that which men in general, or in the
long run, or on the average, hold true, as distinguished from what the
individual under variable and accidental influences holds true. And even
in the case of introspection we found that true cognition resolved
itself into a consensus or agreement as to certain psychical facts.
_Criterion of Illusion._
Now, it behoves us here to examine this assumption, with the view of
seeing how far it is perfectly sound. For it may be that what is
commonly held true does not in all cases strictly answer to the real, in
which case our idea of illusion would have to be extended so as to
include certain common beliefs. This question was partly opened up at
the close of the last chapter. It will be found that the full
discussion of it carries us beyond the scientific point of view
altogether. For the present, however, let us see what can be said about
it from that standpoint of positive science to which we have hitherto
been keeping.
Now, if by common be meant what has been shared by all minds or the
majority of minds up to a particular time, a moment's inspection of the
process of correcting illusion will show that science assumes the
possibility of a common illusion. In the history of discovery, the first
assault on an error was the setting up of the individual against the
society. The men who first dared to say that the sun did not move round
the earth found to their cost what it was to fly in the face of a
common, though illusory, perception of the senses.[151]
If, however, by common be understood what is permanently and unshakably
held true by men in proportion as their minds become enlightened, then
science certainly does assume the truth of common perception and belief.
Thus, the progress of the physical sciences may be described as a
movement towards a new, higher, and more stable consensus of ideas and
beliefs. In point of fact, the truths accepted by men of science already
form a body of common belief for those who are supposed by all to have
the means of testing the value of their convictions. And the same
applies to the successive improvements in the conceptions of the moral
sciences, for example, history and psychology. Indeed, the very meaning
of science appears to be a body of common cognition to which all minds
converge in proportion to their capabilities and opportunities of
studying the particular subject-matter concerned.
Not only so, from a strictly scientific point of view it might seem
possible to prove that common cognition, as defined above, must in
general be true cognition. I refer here to the now familiar method of
the evolutionist.
According to this doctrine, which is a scientific method in so far as it
investigates the historical developments of mind or the order of mental
phenomena in time, cognition may be viewed as a part of the result of
the interaction of external agencies and the organism, as an incident of
the great process of adaptation, physical and psychical, of organism to
environment. In thus looking at cognition, the evolutionist is making
the assumption which all science makes, namely, that correct views are
correspondences between internal (mental) relations and external
(physical) relations, incorrect views disagreements between these
relations. From this point of view he may proceed to argue that the
intellectual processes must tend to conform to external facts. All
correspondence, he tells us, means fitness to external conditions and
practical efficiency, all want of correspondence practical incompetence.
Consequently, those individuals in whom the correspondence was more
complete and exact would have an advantage in the struggle for existence
and so tend to be preserved. In this way the process of natural
selection, by separately adjusting individual representations to
actualities, would make them converge towards a common meeting-point or
social standard of true cognition. That is to say, by eliminating or at
least greatly circumscribing the region of individual illusion, natural
selection would exclude the possibility of a persistent common illusion.
Not only so, the evolutionist may say that this coincidence between
common beliefs and true beliefs would be furthered by social as well as
individual competition. A community has an advantage in the struggle
with other communities when it is distinguished by the presence of the
conditions of effective co-operation, such as mutual confidence. Among
these conditions a body of true knowledge seems to be of the first
importance, since conjoint action always presupposes common beliefs,
and, to be effective action, implies that these beliefs are correct.
Consequently, it may be argued, the forces at work in the action of man
on man, of society on the individual, in the way of assimilating belief,
must tend, in the long run, to bring about a coincidence between
representations and facts. Thus, in another way, natural selection would
help to adjust our ideas to realities, and to exclude the possibility of
anything like a permanent common error.
Yet once more, according to Mr. Herbert Spencer, the tendency to
agreement between our ideas and the environment would be aided by what
he calls the direct process of adaptation. The exercise of a function
tends to the development of that function. Thus, our acts of perception
must become more exact by mere repetition. So, too, the representations
and concepts growing out of perceptions must tend to approximate to
external facts by the direct action of the environment on our physical
and psychical organism; for external relations which are permanent will,
in the long run, stamp themselves on our nervous and mental structure
more deeply and indelibly than relations which are variable and
accidental.
It would seem, from all this, that so long as we are keeping to the
scientific point of view, that is to say, taking for granted that there
is something objectively real answering to our perceptions and
conceptions, the question of the possibility of a universal or
(permanently) common illusion does not arise. Yet a little more
reflection will show us that it may arise in a way. So far as the
logical sufficiency of the social consensus or common belief is accepted
as scientifically proved, it is open to suspicion on strictly scientific
grounds. The evolutionist's proof involves one or two assumptions which
are not exactly true.
In the first place, it is not strictly correct to say that all illusion
involves a practical unfitness to circumstances. At the close of our
investigation of particular groups of illusion, for example, those of
perception and memory, it was pointed out that many of the errors
reviewed were practically harmless, being either momentary and
evanescent, or of such a character as not to lead to injurious action.
And now, by glancing back over the field of illusion as a whole, we may
see the same thing. The day-dreams in which some people are apt to
indulge respecting the remote future have little effect on their
conduct. So, too, a man's general view of the world is often unrelated
to his daily habits of life. It seems to matter exceedingly little, in
general, whether a person take up the geocentric or the heliocentric
conception of the cosmic structure, or even whether he adopt an
optimistic or pessimistic view of life and its capabilities.
So inadequate, indeed, does the agency of natural selection seem to be
to eliminate illusion, that it may even be asked whether its tendency
may not be sometimes to harden and fix rather than to dissolve and
dissipate illusory ideas and beliefs. It will at once occur to the
reader that the illusion of self-esteem, discussed in the last chapter,
may have been highly useful as subserving individual self-preservation.
In a similar way, it has been suggested by Schopenhauer that the
illusion of the lover owes its force and historical persistence to its
paramount utility for the preservation of the species. And to pass from
a recurring individual to a permanently common belief, it is maintained
by the same pessimist and his followers that what they regard as the
illusion of optimism, namely, the idea that human life as a whole is
good, grows out of the individual's irrational love of life, which is
only the same instinctive impulse of self-preservation appearing as
conscious desire. Once more, it has been suggested that the belief in
free-will, even if illusory, would be preserved by the process of
evolution, owing to its paramount utility in certain stages of moral
development. All this seems to show at least the possibility of a kind
of illusion which would tend to perpetuate itself, and to appear as a
permanent common belief.
Now, so far as this is the case, so far as illusion is useful or only
harmless, natural selection cannot, it is plain, be counted on to weed
it out, keeping it within the narrow limits of the exceptional and
individual. Natural selection gets rid of what is harmful only, and is
indifferent to what is practically harmless.
It may, however, still be said that the process of direct adaptation
must tend to establish such a consensus of true belief. Now, I do not
wish for a moment to dispute that the growth of intelligence by the
continual exercise of its functions tends to such a consensus: this is
assumed to be the case by everybody. What I want to point out is that
there is no scientific proof of this position.
The correspondence of internal to external relations is obviously
limited by the modes of action of the environment on the organism,
consequently by the structure of the organism itself. Scientific men are
familiar with the idea that there may be forces in the environment which
are practically inoperative on the organism, there being no
corresponding mode of sensibility. And even if it be said that our
present knowledge of the material world, including the doctrine of the
conservation of energy, enables us to assert that there is no mode of
force wholly unknown to us, it can still be contended that the
environment may, for aught we know, be vastly more than the forces of
which, owing to the nature of our organism, we know it to be composed.
In short, since, on the evolution theory viewed as a scientific
doctrine, the real external world does not directly mirror itself in our
minds, but only indirectly brings our perceptions and representations
into adjustment by bringing into adjustment the nervous organism with
which they are somehow connected, it is plain that we cannot be certain
of adequately apprehending the external reality which is here assumed to
exist.
Science, then, cannot prove, but must assume the coincidence between
permanent common intuitions and objective reality. To raise the question
whether this coincidence is perfect or imperfect, whether all common
intuitions known to be persistent are true or whether there are any that
are illusory, is to pass beyond the scientific point of view to another,
namely, the philosophic. Thus, our study of illusion naturally carries
us on from scientific to philosophic reflection. Let me try to make this
still more clear.
_Transition to Philosophic View._
All science makes certain assumptions which it never examines. Thus, the
physicist assumes that when we experience a sensation we are acted on by
some pre-existing external object which is the cause, or at least one
condition, of the sensation. While resolving the secondary qualities of
light, sound, etc., into modes of motion, while representing the object
very differently from the unscientific mind, he agrees with this in
holding to the reality of something external, regarding this as
antecedent to and therefore as independent of the particular mind which
receives the sense-impression. Again, he assumes the uniformity of
nature, the universality of the causal relation, and so on.
Similarly, the modern psychologist, when confining himself within the
limits of positive science, and treating mind phenomenally or
empirically, or, in other words, tracing the order of mental states in
time and assigning their conditions, takes for granted much the same as
physical science does. Thus, as our foregoing analysis of perception
shows, he assumes that there is an external cause of our sensations,
that there are material bodies in space, which act on our sense-organs
and so serve as the condition of our sense-impressions. More than this,
he regards, in the way that has been illustrated in this work, the
percept itself, in so far as it is a process in time, as the normal
result of the action of such external agents on our nerve-structures, in
other words, as the effect of such action in the case of the healthy and
perfect nervous organism with the average organized dispositions,
physical and psychical; in which case he supposes the percept to
correspond, in certain respects at least, with the external cause as
made known by physical science. And, on the other hand, he looks on a
false or illusory percept as arising in another way not involving, as
its condition, the pre-existence of a corresponding material body or
physical agent. And in this view of perception, as of other mental
phenomena, the psychologist clearly takes for granted the principle that
all mental events conform to the law of causation. Further, he assumes
that the individual mind is somehow, in a way which it is not his
province to inquire into, one and the same throughout, and so on.
The doctrine of evolution, too, in so far as scientific--that is, aiming
at giving an account of the historical and pre-historical developments
of the collective mind in time--agrees with psychology in making like
assumptions. Thus, it conceives an external agency (the environment) as
the cause of our common sensations and perceptions. That is to say, it
represents the external world as somehow antecedent to, and so
apparently independent of, the perceptions which are adjusted to it. And
all this shows that science, while removed from vulgar unenlightened
opinion, takes sides with popular thought in assuming the truth of
certain fundamental ideas or so-called intuitive beliefs, into the exact
meaning of which it does not inquire.
When the meaning of these assumptions is investigated, we pass out of
the scientific into the philosophic domain. Philosophy has to critically
investigate the data of popular thought and of science. It has to
discover exactly what is implied in these fundamental principles. Then
it has to test their value by erecting a final criterion of truth, by
probing the structure of cognition to the bottom, and determining the
proper organ of certain or accurate knowledge; or, to put it another
way, it has to examine what is meant by reality, whether there is
anything real independently of the mind, and if so, what. In doing this
it inquires not only what common sense means by its object-world clothed
in its variegated garment of secondary qualities, its beauty, and so on,
but also what physical science means by its cosmic mechanism of sensible
and extra-sensible matter in motion: whether there is any kind of
objective reality belonging to the latter which does not also belong to
the former; and how the two worlds are related one to another. That is
to say, he asks whether the bodies in space assumed to exist by the
physicist as the antecedent conditions of particular sensations and
percepts are independent of mind and perception generally.[152]
In doing all this, philosophy is theoretically free to upset as much of
popular belief of the persistent kind as it likes. Nor can science find
fault with it so long as it keeps to its own sphere, and does not
directly contradict any truth which science, by the methods proper to
it, is able to establish. Thus, for example, if philosophy finds that
there is nothing real independently of mind, science will be satisfied
so long as it finds a meaning for its assumed entities, such as space,
external things, and physical causes.[153]
The student of philosophy need not be told that these imposing-looking
problems respecting cognition, making, up what the Germans call the
"Theory of Cognition," and the cognate problem respecting the nature of
reality, are still a long way from being settled. To-day, as in the days
of Plato and Aristotle, are argued, in slightly altered forms, the vexed
questions, What is true cognition? Is it a mere efflux from sensation,
a passive conformity of representation to sensation (sensualism or
empiricism)? or is it, on the other hand, a construction of active
thought, involving certain necessary forms of intelligence (rationalism
or intuitivism)?
Again, how are we to shape to ourselves real objective existence? Is it
something wholly independent of the mind (realism)? and if so, is this
known to be what we--meaning here common people and men of science
alike--represent it as being (natural realism), or something different
(transfigured realism)? Or is it, on the contrary, something involving
mind (idealism)? and if so, is it a strictly phenomenal distinction
within our conscious experience (empirical idealism, phenomenalism), or
one of the two poles of subject and object constituted by every act of
thought (rational idealism)? These are some of the questions in
philosophy which still await their final answer.
Philosophy being thus still a question and not a solution, we need not
here trouble ourselves about its problems further than to remark on
their close connection with our special subject, the study of illusion.
Our brief reference to some of the principal inquiries of philosophy
shows that it tends to throw doubt on things which the unreflecting
popular mind holds to be indubitable. Different schools of philosophy
have shown themselves unequally concerned about these so-called
intuitive certainties. In general it may be said that philosophy,
though, as I have remarked, theoretically free to set up its own
standard of certainty, has in practice endeavoured to give a meaning
to, and to find a justification for the assumptions or first principles
of science. On the other hand, it has not hesitated, when occasion
required, to make very light of the intuitive beliefs of the popular
mind as interpreted by itself. Thus, rationalists of the Platonic type
have not shrunk from pronouncing individual impressions and objects
illusory, an assertion which certainly seems to be opposed to the
assumptions of common sense, if not to those of science. On the other
hand, the modern empirical or association school is quite ready to
declare that the vulgar belief in an external world, so far as it
represents this as independent of mind,[154] is an illusion; that the
so-called necessary beliefs respecting identity, uniformity, causation,
etc., are not, strictly speaking, necessary; and so on. And in these
ways it certainly seems to come into conflict with popular convictions,
or intuitive certainties, as they present themselves to the unreflecting
intelligence.
Philosophy seems, then, to be a continuation of that process of
detecting illusion with which science in part concerns itself. Indeed,
it is evident that our special study has a very close connection with
the philosophic inquiry. What philosophy wants is something intuitively
certain as its starting-point, some _point d'appui_ for its
construction. The errors incident to the process of reasoning do not
greatly trouble it, since these can, in general, be guarded against by
the rules of logic. But error in the midst of what, on the face of it,
looks like intuitive knowledge naturally raises the question, Is there
any kind of absolutely certain cognition, any organ for the accurate
perception of truth? And this intimate relation between the scientific
and the philosophic consideration of illusion is abundantly illustrated
in the history of philosophy. The errors of sense, appearing in a region
which to the vulgar seems so indubitable, have again and again set men
thinking on the question, "What is the whole range of illusion? Is
perception, as popularly understood, after all, a big hallucination? Is
our life a dream?"[155]
On the other hand, if our study of the wide range of illusion is fitted
to induce that temper of mind which is said to be the beginning of
philosophy, that attitude of universal doubt expressed by Descartes in
his famous maxim, _De omnibus dubitandum_, a consideration of the
process of correction is fitted to lead the mind on to the determination
of the conditions of accurate knowledge. It is evident, indeed, that the
very conception of an illusion implies a criterion of certainty: to call
a thing illusory, is to judge it by reference to some accepted standard
of truth.
The mental processes involved in detecting, resisting, and overcoming
illusion, are a very interesting subject for the psychologist, though we
have not space here to investigate them fully. Turning to presentative,
and more particularly sense-illusions, we find that the detection of an
illusion takes place now by an appeal from one sense to another, for
example, from sight to touch, by way of verification;[156] now (as in
Myer's experiment) by a reference from sense and presentation altogether
to representation or remembered experience and a process of reasoning;
and now, (as in the illusions of art) conversely, by a transition of
mind from what is suggested to the actual sense-impression of the
moment. In the sphere of memory, again, illusion is determined, as such,
now by attending more carefully to the contents of memory, now by a
process of reasoning from some presentative cognition. Finally, errors
in our comprehensive general representations of things are known to be
such partly by reasoning from other conceptions, and partly by a
continual process of reduction of representation to presentation, the
general to the particular. I may add that the correction of illusion by
an act of reflection and reasoning, which brings the part into
consistent relation with the whole of experience, includes throughout
the comparison of the individual with the collective or social
experience.[157]
We may, perhaps, roughly summarize these operations by saying that they
consist in the control of the lower automatic processes (association or
suggestion) by the higher activities of conscious will. This activity of
will takes the form now of an effort of attention to what is directly
present to the mind (sense-impression, internal feeling, mnemonic image,
etc.), now of conscious reflection, judgment, and reasoning, by which
the error is brought into relation to our experience as a whole,
individual and collective.
It is for the philosopher to investigate the inmost nature of these
operations as they exhibit themselves in our every-day individual
experience, and in the large intellectual movements of history. In no
better way can he arrive at what common sense and science regard as
certain cognition, at the kinds of knowledge on which they are wont to
rely most unhesitatingly.
There is one other relation of our subject to philosophic problems which
I have purposely left for final consideration. Our study has consisted
mainly in the psychological analysis of illusions supposed to be known
or capable of being known as such. Now, the modern association school
professes to be able to resolve some of the so-called intuitions of
common sense into elements exactly similar to those into which we have
here been resolving what are acknowledged by all as illusions. This fact
would seem to point to a close connection between the scientific study
of illusion and the particular view of these fundamental intuitions
taken by one philosophic school. In order to see whether there is really
this connection, we must reflect a little further on the nature of the
method which we have been pursuing.
I have already had occasion to rise the expression "scientific
psychology," or psychology as a positive science, and the meaning of
this expression must now be more carefully considered. As a positive
science, psychology is limited to the function of analyzing mental
states, and of tracing their origin in previous and more simple mental
states. It has, strictly speaking, nothing to do with the question of
the legitimacy or validity of any mental act.
Take a percept, for example. Psychology can trace its parentage in
sensation, the mode in which it has come by its contents in the laws of
association. But by common consent, a percept implies a presentative
apprehension of an object now present to sense. Is this valid or
illusory? This question psychology, as science, does not attempt to
answer. It would not, I conceive, answer it even if it were able to make
out that the whole mental content in the percept can be traced back to
elementary sensations and their combinations. For the fact that in the
chemistry of mind elements may combine in perfectly new forms does not
disprove that the forms thus arising, whether sentiments or
quasi-cognitions, are invalid. Much less can psychology dispute the
validity of a percept if it cannot be sure that the mind adds nothing to
sensation and its grouping; that in the genesis of the perceptive state,
with its intuition of something external and now present as object,
nothing like a form of intelligence is superimposed on the elements of
sensation, giving to the result of their coalescence the particular
unity which we find. Whether psychology as a positive science can ever
be sure of this: whether, that is to say, it can answer the question,
"How do we come by the idea of object?" without assuming some particular
philosophic or extra-scientific theory respecting the ultimate nature of
mind, is a point which I purposely leave open.
I would contend, then, that the psychologist, in tracing the genesis of
the percept out of previous mental experiences, no more settles the
question, What is the object of perception? than the physicist settles
it in referring the sense-impression (and so the percept) to a present
material agent as its condition.
The same applies to our idea of self. I may discover the concrete
experiences which supply the filling in of the idea, and yet not settle
the question, Does intelligence add anything in the construction of the
form of this idea? and still less settle the question whether there is
any real unity answering to the idea.
If this is a correct distinction, if psychology, as science, does not
determine questions of validity or objective meaning but only of
genesis, if it looks at mental states in relation only to their temporal
and causal concomitants and not to their objects, it must follow that
our preceding analysis of illusion involves no particular philosophic
theory as to the nature of intelligence, but, so far as accurate,
consists of scientific facts which all philosophic theories of
intelligence must alike be prepared to accept. And I have little doubt
that each of the two great opposed doctrines, the intuitive and the
associational, would claim to be in a position to take up these facts
into its particular theory, and to view them in its own way.
But in addition to this scientific psychology, there is another
so-called psychology, which is, strictly speaking, philosophic. This, I
need hardly say, is the association philosophy. It proceeds by analyzing
certain cognitions and sentiments into their elements, and straightway
declaring that they mean nothing more than these. That is to say, the
associationist passes from genesis to validity, from the history of a
conscious state to its objective meaning. Thus, from showing that an
intuitive belief, say that in causation, is not original (in the
individual or at least in the race), it goes on to assert that it is not
a valid immediate cognition at all. Now, I am not concerned here to
inquire into the logical value of this transition, but simply to point
out that it is extra-scientific and distinctly philosophic. If logically
justifiable, it is so because of some plainly _philosophic_ assumption,
as that made by Hume, namely, that all ideas not derived from
impressions are to this extent fictitious or illusory.
And now we are in a position to understand the bearing of our scientific
analysis of acknowledged illusions on the associationist's treatment of
the alleged illusions of common sense. There is no doubt, I think, that
some of the so-called intuitions of common sense have points of analogy
to acknowledged illusions. For example, the conviction in the act of
perception that something external to the mind and independent of it
exists, has a certain superficial resemblance to an hallucination of
sense; and moreover, the associationist seeks to explain it by means of
these very processes which underlie what is recognized by all as
sense-illusion.[158] Again, it may be said that our notions of force and
of a causal nexus in the physical world imply the idea of conscious
energy as known through our muscular sensations, and so have a
suspicious resemblance to those anthropomorphic illusions of which I
have spoken under Illusions of Insight. Once more, the consciousness of
freedom may, as I have suggested, be viewed as analogous in its form and
its mode of origin to illusions of introspection. As a last example, it
may be said that the mind's certain conviction of the innateness of some
of its ideas resembles those illusions of memory which arise through an
inability to think ourselves back into a remote past having a type of
consciousness widely unlike that of the present.
But now, mark the difference. In our scientific analysis of popularly
known illusions, we had something by which to determine the illusory
character of the presentation or belief. We had a popularly or
scientifically accepted standard of certainty, by a reference to which
we might test the particular _soi-disant_ cognition. But in the case of
these fundamental beliefs we have no such criterion, except we adopt
some particular philosophic theory, say that of the associationist
himself. Hence this similarity in structure and origin cannot in itself
be said to amount to a proof of equality of logical or objective value.
Here again it must be remarked that origin, does not carry validity or
invalidity with it.[159]
We thus come back to our starting-point. While there are close
relations, psychological and logical, between the scientific study of
the ascertained facts of illusion and the philosophic determination of
what is illusory in knowledge as a whole, the two domains must be
clearly distinguished. On purely scientific ground we cannot answer the
question, "How far does illusion extend?" The solution of this question
must be handed over to the philosopher, as one aspect of his problem of
cognition.
One or two remarks may, perhaps, be hazarded in concluding this account
of the relation of the scientific to the philosophic problem of
illusion. Science, as we have seen, takes its stand on a stable
consensus, a body of commonly accepted belief. And this being so, it
would seem to follow, that so far as she is allowed to interest herself
in philosophic questions, she will naturally be disposed to ask, What
beliefs are shared in by all minds, so far as normal and developed? In
other words, she will be inclined to look at universality as the main
thing to be determined in the region of philosophic inquiry. The
metaphysical sceptic, fond of daring exploits, may break up as many
accepted ideas as he likes into illusory _débris_, provided only he has
some bit of reality left to take his stand on. Meanwhile, the scientific
mind, here agreeing with the practical mind, will ask, "Will the beliefs
thus said to be capable of being shown to be illusory ever cease to
exercise their hold on men's minds, including that of the iconoclast
himself? Is the mode of demonstration of such a kind as to be likely
ever to materially weaken the common-sense 'intuition'?"
This question would seem to be most directly answerable by an appeal to
individual testimony. Viewed in this light, it is a question for the
present, for some few already allege that in their case philosophic
reasonings exercise an appreciable effect on these beliefs. And so far
as this is so, the man of scientific temper will feel that there is a
question for him.
It is evident, however, that the question of the persistence of these
fundamental beliefs is much more one for the future than for the
present. The correction of a clearly detected illusion is, as I have
more than once remarked, a slow process. An illusion such as the
apparent movement of the sun will persist as a partially developed error
long after it has been convicted. And it may be that the fundamental
beliefs here referred to, even if presumably illusory, are destined to
exercise their spell for long ages yet.
Whether this will be the case or not, whether these intuitive beliefs
are destined slowly to decay and be dissolved as time rolls on, or
whether they will retain an eternal youth, is a question which we of
to-day seem, on a first view of the matter, to have no way of answering
which does not assume the very point in question--the truth or falsity
of the belief. This much may, however, be said. The associationist who
resolves these erroneous intuitions into the play of association, admits
that the forces at work generating and consolidating the illusory belief
are constant and permanent forces, and such as are not likely to be less
effective in the future than they have been in the past. Thus, he
teaches that the intuition of the single object in the act of perception
owes its strength to "inseparable association," according to which law
the ideas of the separate "possibilities of sensation," which are all we
know of the object, coalesce in the shape of an idea of a single uniting
substance. He adds, perhaps, that heredity has tended, and will still
tend, to fix the habit of thus transforming an actual multiplicity into
an imaginary unity. And in thus arguing, he is allowing that the
illusion is one which, to say the least of it, it will always be
exceedingly difficult for reason to dislodge.
In view of this uncertainty, and of the possibility, if not the
probability, of these beliefs remaining as they have remained, at least
approximately universal, the man of science will probably be disposed to
hold himself indifferently to the question. He will be inclined to say,
"What does it matter whether you call such an apparently permanent
belief the correlative of a reality or an illusion? Does it make any
practical difference whether a universal 'intuition,' of which we cannot
rid ourselves, be described as a uniformly recurring fiction of the
imagination, or an integral constitutive factor of intelligence? And, in
considering the historical aspect of the question, does it not come to
much the same thing whether such permanent mental products be spoken of
as the attenuated forms or ghostly survivals of more substantial
primitive illusions (for example, anthropomorphic representations of
material objects, 'animistic' representations of mind and personality),
or as the slowly perfected results of intellectual evolution?"
This attitude of the scientific mind towards philosophic problems will
be confirmed when it is seen that those who seek to resolve stable
common convictions into illusions are forced, by their very mode of
demonstration, to allow these intuitions a measure of validity. Thus,
the ideas of the unity and externality attributed to the object in the
act of perception are said by the associationist to answer to a matter
of fact, namely, the permanent coexistence of certain possibilities of
sensation, and the dependence of the single sensations of the individual
on the presence of the most permanent of these possibilities, namely,
those of the active or muscular and passive sensations of touch, which
are, moreover, by far the most constant for all minds. Similarly, the
idea of a necessary connection between cause and effect, even if
illusory in so far as it expresses an _objective_ necessity, is allowed
to be true as an expression of that uniformity of our experience which
all scientific progress tends to illustrate more and more distinctly.
And even the idea of a permanent self, as distinct from particular
fugitive feelings, is admitted by the associationist to be correct in so
far as it expresses the fact that mind is "a series of feelings which
is aware of itself as past and future." In short, these "illusory
intuitions," by the showing of those who affirm them to be illusory, are
by no means hallucinations having no real object as their correlative,
but merely illusions in the narrow sense, and illusions, moreover, in
which the ratio of truth to error seems to be a large one.
It would thus appear that philosophy tends, after all, to unsettle what
appear to be permanent convictions of the common mind and the
presuppositions of science much less than is sometimes imagined. Our
intuitions of external realities, our indestructible belief in the
uniformity of nature, in the nexus of cause and effect, and so on, are,
by the admission of all philosophers, at least partially and
_relatively_ true; that is to say, true in relation to certain features
of our common experience. At the worst, they can only be called illusory
as slightly misrepresenting the exact results of this experience. And
even so, the misrepresentation must, by the very nature of the case, be
practically insignificant. And so in full view of the subtleties of
philosophic speculation, the man of science may still feel justified in
regarding his standard of truth, a stable consensus of belief, as above
suspicion.
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INDEX.
A.
Abercrombie, Dr. J, 141, note[82], 278.
Abnormal life, relation of,
to normal, 1, 120, 121, 124, 182, 277, 284, note[132], 336;
effects of amputation, 62;
modification of sensibility in, 65;
gross sense-illusions of, 111, hallucinations of, 118;
sense of personal identity in, 289.
Active, stage in perception, 27;
illusion distinguished from passive, 45, 332-334.
Actor. _See_ Theatre.
Adaptation, illusion as want of, 124, 188, 339.
Æsthetic intuition, 213;
illusions of, 214.
After-dreams, 144, 183.
After-sensation, after-impression, 55, 115.
Anæsthesia, 65.
Ancestral experience, results of, 281.
Animals, recognition of portraits by, 105;
expectation of, 298.
Anthropomorphism, 225, 360.
Anticipation. _See_ Expectation.
Apparitions. _See_ Hallucination.
Aristotle, 130.
Art, illusions of, 77, 104.
Artemidoros, 129.
Association, laws of, in perception, 22;
in dreams, 153, 156;
link of resemblance in dreams, 159;
associative dispositions in dreams, 169;
effect of, in insight, 221;
inseparable, 359.
Associationist, views of, 349, 352, 355.
Attention, involved in perception 21;
absence of, in sense-illusion, 39, 87;
relation of, to recognition of objects, 90;
expectant, 93;
attitude of, in dreaming, 137, 172;
to internal mental states, 194;
absence of, in errors of insight, 228.
Authority, influence of, in introspection, 210;
in belief, 325.
Autobiography, errors connected with, 276, 280.
Automatic activity of centres, in hallucinations, 113;
in dreams, 136, 151;
automatic intellectual processes, 300, 335, 352.
B.
Baillarger, J., 13, note[1], 113, note[57], 119,
notes[64] and [65], 120, note[66].
Bain, Dr. A., 32, note[12], 117, note[60], 190.
Beattie, J., 141, note[82].
Beauty, sentiment of, 206, 213.
Belief, immediate, 14, 15, 294;
simple and compound, 296;
illusory forms of, 297;
simple expectation, 297;
expectation, of extra-personal experiences, 307;
retrospective, 309;
in persistent objects and persons, 312;
self-esteem, 315;
representation of classes of things, 322;
representations of mankind, 322;
representation of life and the world as a whole, 322;
as predisposition to error, 324;
amount of divergence in, 325;
tendency towards convergence in, 326.
Beneficial, correct knowledge as, 340;
illusion as, 342.
Berkeley, Bishop, 218, 349, note[154].
Binet, A., 53, note[20].
Boismont, Brierre de, 11, note[1].
Börner, J., 146.
Braid, James, 186, 187.
Brewster, Sir D., 42, 73, 81, 116.
Brücke, E., 77, note[38].
Byron, Lord, 116.
C.
Carpenter, Dr. W.B., 32, note[12], 108, 110, note[56], 186, 231,
note[111], 265, note[125], 276.
Castle-building, as illusory perception, 3, 99.
Cause, idea of, in science, 344;
reality of relation of, 347, 349, 356, 360.
Change, a condition of conscious life, 252, 287, note[133].
Childhood, our recollections of, 263, 269.
Children, curiosity of, 175, 180;
estimate of time by, 256;
confusion of dream and waking life by, 276;
imagination of, 279;
self-assertion of, 319;
intellectual condition of, 357, note[159].
Clarke, Dr. E.H., 117.
Classification, in recognition of sensation, 21;
in recognition, of object, 24;
in introspective recognition, 193.
Clifford, Professor W.K., 56, note[24].
Coalescence, of sensations, 43, 52;
of dream-images, 162;
of internal feelings, 196;
of mnemonic images, 265.
Coenæsthesis, 41, 99, 145, 286, 288.
Cognition, immediate or intuitive, 5, 14-16, 294;
presentative and representative, 9, 13, 217, 330;
nature of, in dreams, 168, 172;
nature of, generally, 295, 331;
philosophic problems of, 346.
Colour, external reality of, 8, 37;
illusory perception of, 37, 88;
subjective complementary colours (colour-contrast), 67, 83.
Coloured media, objects seen through, 82.
Common cognition, and truth, 337;
genesis and validity of, 353.
Common experience distinguished from
individual, 26, 27, 137, 209, 214, 336, 351;
illusion as, 47,325, 337.
Common sense, intuitions of, 346, 349, 352, 357.
Complementary colours, 67, 83.
Concave, apparent conversion of, into convex, 84.
Conjuror, tricks of, 56, 106.
Consciousness, veracity of, 192, 205;
inspection of phenomena of, 196;
of self, 283, 285.
Consensus, the standard of truth, 7, 8, 211, 325, 338, 357.
Conservation of energy, 343.
Construction, rational, in dreams, 170.
Continuum, the perception of the world as, 52, 56, note[24].
Correction of illusion, in sense-illusion, 38, 124, 137;
dreams, 182;
introspection, 210;
insight, 229;
memory, 291;
historical correction 338;
intellectual processes involved in, 351.
Criterion of illusion, 337.
Cudworth, R., 161
D.
Deception of the senses, 19;
self-deception, 200;
conscious deception of others, 222.
Delboeuf, J., 175, note[97], 235, note[113].
_Delirium tremens_, 118, note[62].
Democritus, 130.
De Quincey, 253, 280.
Descartes, R., 116, 350.
Dickens, Charles, 277.
Direction, illusory sense of, in vision, 66, 71, 73;
in hearing, 72, 75.
Disease. _See_ Abnormal life.
Dissolution. _See_ Evolution.
Doubt, starting-point in philosophy, 350.
Dreams, relation of, to illusions of sense, 18, 130;
and waking experience, 127;
theories of, 128;
physiology of, 131;
extent of, in sleep, 132;
psychological conditions of, 136;
excitants of, 139, 143;
exaggeration in, 147;
symbolism of, 149;
as results of automatic activity of centres, 151;
as results of association, 153;
structure of, 156;
incoherent, 156;
coherent, 161;
action of feeling in, 164;
play of associative dispositions in, 168;
co-operation of attention and intelligence in, 172;
limits of intelligence in, 180;
after-dreams, 183, 274;
relation of, to hypnotic condition, 185;
experience of, in relation to errors of memory, 273.
E.
Eccentricity, law of, 59.
Ego. _See_ Self.
Emotion, and illusion of perception, 103;
and hallucination, 115;
and bodily sensations, 150;
control of dreams by, 164;
introspection of, 199;
and illusion of introspection, 203;
and æsthetic intuition, 213;
and illusion of memory, 270;
and illusion of belief, 306, 324;
and cognition generally, 357, note[159].
Empiricism, philosophic, 348.
_Ennui_, and sense of time, 250.
Environment, sources of sense-illusion in, 47, 48, 70;
view of, in mental disease, 290, 326;
view of, in normal life, 323;
action of, in assimilating belief, 339.
Error, immediate and mediate, 6, 334.
Esquirol, J.E.D., 12, note[2].
Evolution, relation of, to dissolution, 122;
of power of introspection, 209;
of power of insight, 230;
and self-assertion, 320;
evolutionist's view of error, 339;
doctrine of, as science, 346.
Exaggeration, in interpretation of sensations, 65;
in dream-interpretation, 147;
in memory, 269.
Expectation, preliminary to perception, 30;
and illusory perception, 93, 102, 106;
nature of, 295;
and memory, 298;
of new experience, 301;
of remote events, 302;
measurement of duration in, 302;
action of imagination in, 305;
extension of meaning of, 307, 308.
Experience, effect of, in perception, 22, 68, 85, 86, 91;
external and internal, 194, 210;
revivals of waking, in dreams, 152;
effects of present, on retrospection, 267;
anticipation of new, 301.
External world. _See_ World.
F.
Fallacy and illusion 6, 335;
of testimony, 265.
Familiarity, sense of, in new objects, 272, 281.
Fechner, G.T., 51.
Ferrier, Dr., 32, note[12], 58, note[26].
Fiction, as producing illusion, 278, 279, 311.
Fitness. _See_ Adaptation.
Flattery, _rationale_ of, 200, 222.
Forgetfulness and illusion, 278, 279, 311.
Free-will, doctrine of, 207, 342, 356.
Future. _See_ Expectation.
G.
Galton, F., 117.
Ghosts. _See_ Hallucination.
Goethe, 116, 117, 280 and note[131].
Griesinger, W., 13, note[2], 63, note[31], 66, note[32], 115, 118,
note[62], 119, note[64], 120, note[66], 290, note[135], 327,
note[146].
Gruithuisen, 143, 144.
Gurney, E., 224, note[109].
H.
Hall, G.S., 186, note[102].
Hallucination, and illusion, 11, 109, 111, 112, 121;
and subjective sensation, 63, 109, 121;
sensory and motor, 66;
nervous conditions of, 112-114;
incomplete and complete, 113;
as having either central or peripheral origin, 113;
causes of, classified, 115;
in sane condition, 116;
in insanity, 118;
visual and auditory, 119;
dreams regarded as, 139, 151;
hypnagogic, 143;
after-dreams and ghosts, 183;
of memory, 271;
relation of, to errors of belief, 322;
intuition of external world regarded as, 355.
Happiness, feeling of, 200.
Harmful, illusion as, 188, 229, 292, 339.
Harmless, illusions as, 124, 292, 341.
Hartley, D., 139, 256, note[124], 279.
Hearing, as mode of perception, 34, 48;
localization of impression in, 60;
sense of direction in, 72;
activity of, in sleep, 140;
and muscular sense, 171.
Heidenhain, Dr., 186-188.
Helmholtz, H., 22, 23, note[7], 44, 51, 54 and note[22], 55, note[23],
57, 67, note[33], 78, note[39], 80, 85, note[43], 88, 90, 207,
note[105].
Heraclitus, 137.
Heredity, and illusion of memory, 280;
action of, in perpetuating intuition, 359.
Hering, E., 67, note[33].
Hodgson, Shadworth H., 347, note[153].
Holland, Sir H., 277.
Hood, Thomas, 146.
Hope, illusory. _See_ Expectation.
Hoppe, Dr. J.I., 51, 58, note[26].
Horwicz, A., 145, note[85].
Hume, D., 355.
Huxley, Professor T., 119, note[1].
Hyperæsthesia, 65.
Hypnotism, 185.
Hypochondria, 65.
Hypothesis, as illusory, 310, 311.
I.
Idealism, 348.
Identity, cases of mistaken, 267.
Identity, personal, confusion of, in dreams, 163;
consciousness of, 241, 267, 282, 285;
illusory forms of, 283;
gross disturbances of, in normal life, 287;
in abnormal life, 289;
momentary confusions of, 293.
Illusion, definition of, 1;
varieties of, 9;
extent of, 328;
_rationale_ of, 331, 337.
Image (physical). _See_ Reflection.
Image (mental), in perception, 22;
seat of, 32;
in dreams, 138;
mnemonic, 236.
Imagination, play of, in perception, 95, 99;
and sense-illusion, 106;
nature of, in dreaming, 136, 161;
as antecedent of dream, 152, 158;
as poetic interpretation of nature, 224;
memory corrupted by effect of past, 264, 273, 277;
present, creating the semblance of recollection, 267, 271;
play of, in expectation, 305;
as element of illusion generally, 333.
Immediate. _See_ Cognition.
Individual, and common experience, 26, 27, 137, 209, 214, 336;
dream-experience as, 44, 68;
internal experience as, 209;
memory as, 232;
belief and truth, 338.
Inference, and immediate knowledge, 6, 334;
in perception, 22, 26, 68;
in belief, 295.
Innate, recollection as, 280;
principles, 295, 356.
Insane, sense-illusions of, 63, 65, 111;
hallucinations of, 118;
dreaming and state of, 182;
mnemonic illusions of, 278, 289;
beliefs of, 327.
Insight, nature of, 217;
illusions of, defined, 220;
passive illusions of, 220;
histrionic illusion, 222;
active illusions of, 223;
poetic interpretation of nature, 224;
value of faculty of, 228.
Interpretation, in correct perception, 22;
of impression and experience, 70;
and volition, 95;
and fixed habits of mind, 101;
and temporary attitude of mind, 102;
of sensations in dreams, 137, 147;
of internal feelings, 203;
of others' feelings, 217;
of nature by poet, 225;
recollection as, 242.
Introspection, nature of, 14, 189;
illusory forms of, 190;
confusion of inner and outer experiences, 194;
inaccurate inspection of feelings, 196;
presentation and representation confused, 199;
feelings and inferences from these, 203;
moral self-scrutiny, 204;
philosophic, 205;
value of, 208.
Intuition. _See_ Cognition.
Intuitivism, 348.
J.
Jackson, Dr. J. Hughlings, 27, note[9], 33, 123, note[67].
Johnson, Dr., 116.
K.
_Klang_, as compound sensation, 53.
Knowledge. _See_ Cognition.
L.
Language, function of, 195.
Leibnitz, 133.
Lélut, L.F., 120, note[66].
Lessing, G. E., 133, note[73].
Leuret, 290, note[135].
Lewes, G.H., 28, 32, note[12], 52, note[30], 62, note[1], 68,
note[35], 89, note[45], 115, note[58], 150.
Life, our estimate of, 323, 326, 327.
Light, sensation and perception of, 59;
effects of reflection and refraction, of, 73;
representation, of, in painting, 88, 91;
action of, in sleep, 140.
Localization, as local discrimination of sensations, 52;
as localizing of sensations, 59, 60;
illusory, 61, 82;
in hallucination, 118, 119;
in dreaming, 148;
of events in time, in memory, 238, 245;
in expectation, 304.
Locke, 133, note[73].
Lotze, H., 60, note[29].
Lover, illusion of, 224, 227, 342.
Luminosity of painting, 88, 91.
Lustre, as compound sensation, 54.