likeness and unlikeness that thought shows itself most clearly to be
a synthetic process. Thinking has in a special manner to do with the
detection of similarity and dissimilarity or difference. Such relating
by way of difference or agreement is what we ordinarily understand by
comparison.
The relations of similarity and dissimilarity as comprehensive
relations connecting presentations remote as well as proximate in
time are spoken of as internal and thus marked off from the external
relations of time and place. It is true as we have just seen that
they are involved along with the latter. Thus in discerning the
relations of the parts of an object, we must differentiate them. Yet
the two modes of relating are distinct. I discriminate two colors in
local juxtaposition not _quâ_ juxtaposed but _quâ_ different in their
quality. The juxtaposition may greatly assist the discriminative
process, but this circumstance does not make the juxtaposition and the
qualitative difference one whit less distinct as relations.
It may be added that the greater comprehensiveness of the so-called
internal relations is seen in the circumstance that the relations of
time and place, just like the separate qualities or attributes of
objects, are themselves modes of similarity and dissimilarity. Thus the
relation of local contiguity between two elements is something _common_
to these and other contiguous pairs. Moreover, it is evident that in
such a case each element is recognised as having a different position
from the other. Similarity with the temporal relations of events.
_Comparison._—We may now glance at the operations here brought under
the head of comparison, the bringing of different presentative or
representative materials before the mind simultaneously and keeping
them in consciousness in order to note their relations of similarity or
dissimilarity. Here as in the case of Analysis or Abstraction we shall
illustrate the process by selecting relatively simple modes of the
operation carried out on immediately presented sense-material.
_Likeness and Difference._—We may here assume that likeness and
unlikeness are two perfectly distinct relations. To apprehend a
similarity between two sensations, say tones, is an intellectual
process which we all recognise as radically unlike that of apprehending
a difference.
Yet while the consciousness of likeness and that of difference are thus
radically distinct, as psychical processes, it is evident that the
relations of likeness and difference are presented together in close
connection. As we all know similarity discloses itself in the midst of
difference. This is obvious in the case of all complex presentations,
as when we assimilate two objects on the ground of a color resemblance.
Not only so, since even in the case of sensation-elements (e. g.
color-sensations) likeness is a thing of degree shading off from
perfect likeness or indistinguishableness to just recognisable
affinity, it follows that here, too, likeness and difference are given
together in mutual implication.
Since resemblance and difference are thus uniformly presented together,
it is to be expected that comparison will commonly include the two
processes, assimilation and discrimination. And this is so. We see
likeness amid difference, e. g. a common trait in two faces along with
striking dissimilarities. On the other hand we contrast two objects in
respect of some _common_ quality as color, form, beauty and so forth,
which common element constitutes the ground or _fundamentum_ of the
comparison.
At the same time it is evident that the one process usually, if not
in all cases, preponderates over the other. We are now specially
interested in the likeness of two objects, say two faces, or two
literary styles, the moment after, perhaps, in their differences.
Accordingly we may say that comparison is the noting of likeness
against a dimly apprehended background of difference, or a difference
against a dimly apprehended background of similarity.
_Conditions of Comparison._—Comparison whether specially directed to
likeness or unlikeness has certain common conditions. As in the case of
Abstraction these conditions may be divided into objective, or those
involved in the nature or concomitants of the presentations considered
as external objects, or objects of common perception; and subjective or
those connected with the nature of the individual mind. As I have given
a full account[98] of these elsewhere, I must content myself here with
a general remark or two on the subject.
[98] In _Mind_, x. p. 489 et seqq.
Of the objective conditions the most important are the following:
(_a_) There must be a moderate and favorable degree of strength or
intensity in the presentations to be compared. We compare fairly bright
colors better than very dull ones. (_b_) The common factor or _ground_
of comparison must be sufficiently distinct. We cannot compare two
tones in respect of pitch if this is unsteady. (_c_) Comparison is
greatly aided by juxtaposition in space or time. Thus local proximity
is a condition of a nice comparison of colors. With respect to
temporal conditions it was found by Fechner and has been confirmed by
others that immediate succession is more helpful to comparison than
simultaneity. We compare sensations of weight, tone, etc., best of all
when they are made to succeed one another.
With respect to subjective conditions, comparison will, it is obvious,
be assisted by a good power of concentration. It will also be aided by
a special sensibility for, and interest in, the particular sensuous
material: witness the musician's comparison of tones as to pitch,
purity, etc. Lastly reference may be made to special preparation or
mental preadjustment. It is manifest that if we are expecting to see
two things like one another we shall in general be more disposed to do
so; similarly if we are on the lookout for difference.
It may be added that there is a special interest in likeness _as such_,
and also in difference. Such interest predisposes a person to detect
the one relation rather than the other. Hence the familiar observation
that some people are particularly acute in seeing likenesses, e. g. in
faces, whereas others are habitually more observant of differences.
_Connection between Analysis and Comparison._—There is a close
connection between the two directions of thought-activity just dealt
with. To begin with, it has become evident that in the processes of
comparison, analysis is always involved. Sometimes the analysis seems
to precede the comparison, as when we are asked to compare two flowers
in respect of their color. In other cases it appears rather as the
result of comparison. Thus it is by successive comparisons of different
members of a class of things, as flowers, that we gradually come to
analyse out the common features of the group.
While comparison thus involves abstraction, abstraction even in
the case of a single object may be said to involve the rudiments
of comparison. Thus in analytically singling out for consideration
the spherical form of a rain drop, we implicitly and subconsciously
assimilate it to other previously known spherical objects. But for this
vague imperfect accompaniment of assimilation, the analytic separation
of the constituent would be difficult if not impossible. Such a
subconscious reference to one or more similar things helps to direct
the operation of analysis by intensifying and rendering prominent for
the moment the particular constituent assimilated through the addition
of an ideational element to the sensation.[99]
[99] This is well brought out by W. James, _Principles of
Psychology_, i. p. 434 et seqq.
It follows that the thought-process is one process having two aspects
or distinguishable factors. Either of these may become predominant
according to special circumstances. In this way we obtain two varieties
of operation, viz. Analysis or Abstraction, in which the recognition of
likeness is subconscious, and Assimilative Comparison where the process
of analysis is preliminary and subordinate to a conscious apprehension
of likeness.
A somewhat like relation holds between analysis as a subconscious
process of differentiation and a conscious act of discrimination. Thus
in analysing a clang we must, agreeably to what was said above, have
a vague impression of the difference between one tone and another. And
such subconscious differentiation readily becomes the starting-point in
a full conscious apprehension by an act of comparing attention of the
differences between the several ingredients.[100]
[100] Stumpf uses the term Analysis for the mere vague
detection of plurality of elements in a sensation-complex
which he considers to be distinct from, and preliminary to
a discrimination of them as different one from the other.
_Tonpsychologie_ ii. p. 104 et seqq.
Thus far we have been occupied with the two fundamental processes
in thought and we have illustrated these in their simplest form
as employed about presentations or their equivalents, concrete
representations. But as already pointed out what we mean by thought
is the representation of things as classes or generalities. All the
more interesting and momentous problems relating to thought, such
as the question whether the lower animals think or reason as we do,
have reference to such _general_ thinking. We have now to examine the
processes involved in this thinking.
These fully developed thought-processes are marked off by the use of
what is known as the general idea or notion such as _man_ or _virtue_.
Such general ideas when reduced to a precise form as by the logician
are spoken of as concepts. And since the science of logic assumes
thinking to take place by help of such conceptual products we may
also speak of these full or explicit thought-processes as Conceptual
Thought.[101]
[101] The use of such expressions must not, however, blind
us to the fact that a concept strictly speaking is something
logical, an _ideal_ form of the general idea rarely if ever
realised in our actual thinking processes. Of this more
presently.
_General Ideas and their Formation._—In seeking to trace the
development of this general thinking we have first of all to consider
the nature and origin of general ideas. It is evident that we only
think about things generally in a distinct manner when we are able to
form such ideas. Thus I cannot think out the proposition 'The mushroom
is a fungus' until I am able to form the general ideas mushroom and
fungus. The difficult problems respecting the nature of thought, its
relation to language, and its extension beyond man to the lower
animals, have been discussed in close connection with the nature and
origin of general ideas.
A general idea may for our present purpose be defined as an idea having
a general import or reference. Thus a child's idea of dog, home, or
father, becomes general when he consciously employs the term as the
sign of this, that, and any other particular object which may answer
to a certain description or be found to present certain characteristic
attributes or traits; or, as the logicians express it, a general idea
is a representation of a general class of things.[102]
[102] The reader must be careful to distinguish the meaning of
the term class as here used from its meaning when applied to a
definite number of objects viewed as a collection, as a class
of children in a school. In thinking of man as a (logical)
class I do not represent a definite number at all; nor do I
represent men as a collection. It would be more correct to say
that I am representing in a more or less distinct way the fact
that this, that, and an indefinite list of other things are
related as like or answering to one description. How this mode
of representation is effected will appear presently.
Now it is evident that general ideas as thus defined are reached slowly
and by degrees. It is exceedingly doubtful whether any of the lower
animals possess them. The baby does not possess them and even after
attaining to speech remains for a long time with only the rudiments
of them. In their perfected articulate form as required for exact
scientific thought they are confined to a few highly trained minds.
_Generic Images._—The first stage in the formation of such general
ideas is the welding together of a number of concrete images into what
has been called a generic image. The idea tree or house may be taken
as an example. Such generic images appear to be formed by a process of
assimilative cumulation. Let us suppose that a child after observing
one dog, sees a second. In this case the strong resemblance in the
second to the first effects a process of assimilation analogous to
automatic or "unconscious" assimilation. That is to say, the percept
corresponding to the second animal is instantly fused with the
surviving image of the first by reason of easily apprehended points
of likeness. By such successive assimilations a cumulative effect is
produced which has been likened to that of the superposition of a
number of photographic impressions received from different members of a
class, (e. g. criminal,) whereby common features get accentuated and so
a typical form is produced.[103]
[103] For an account of such composite photographic pictures,
and their analogy to generic (mental) images, see Mr. F.
Galton's _Inquiries into Human Faculty_. Appendix, "Generic
Images."
Such a process of deepening and accentuating common traits and effacing
individual or variable ones can only be looked on as a tendency never
perfectly fulfilled. Interesting differences would in all cases tend to
reinstate themselves. Thus my own generic image of a church happens to
be a building with a tall spire, because the finest church in my native
town was of this form. Recent examples would also tend to contribute
variable peculiarities. Thus the baby's generic image of a dog might
have the distinguishing characters of the dog last seen.
This process of cumulative assimilation would be largely passive and
independent of those active processes of comparison, just described.
It would further be capable of being carried forward (to some extent
at least) independently of language. Hence we may, with some degree of
confidence, attribute generic images to the child before he comes to
the use of words and to many of the lower animals. Thus it is highly
probable that a baby of six months forms a generic image of the human
face out of the percepts answering to its mother's face, nurse's face,
etc., and that when suffering from loneliness it has this image in
its mind. Similarly a predatory animal may be supposed to compound a
generic image out of the percepts gained from this, that, and the other
specimen of his prey, so that when seized with hunger, this typical
image is recalled.
In order to illustrate what is meant by a generic image, it is
important to take the case of a pure representation detached from
a presentation. Thus we cannot say that because a diving bird
recognises a new sheet of water, it must have at the moment, a
generic image answering to water. The recognition of a thing does not
imply a distinct representation of the thing as previously seen. The
presentative and representative ingredients are fused in this case, or
to express it otherwise, the image is latent and undeveloped. Similarly
with respect to such rudimentary processes of conception or general
ideation as those here considered. We can only attribute a developed
and detached generic image to baby or animal when we have reason to
think that these occur in the absence of percepts, e. g. in states of
desire, in dreams, and so forth.[104]
[104] The argument in support of the proposition that generic
images, or (as the writer calls them) "recepts" are actually
reached by the lower animals is ably set forth by Dr. Romanes,
_Mental Evolution in Man_, p. 51 et seqq.
_Relation of Generic Image to General Idea._—The question still
remains how far such generic images are, properly speaking, _general_
ideas in the sense defined above. Is, for example, the typical face
that is pictured by the lonely infant thought of as something common to
this, that, and the other concrete object? Does it carry with it any
clear consciousness of a general class of things? There is no certain
proof that this is so. It must be remembered here that the mental
image corresponding to one and the same individual object, as the
infant's mother, is composite also and in the same way as the generic
image. Thus the baby forms the image of its mother out of a number of
practically unlike percepts, corresponding to varying appearances of
the object in different positions, different light, different dress,
and so forth.[105] Generic images accordingly differ not in kind, but
only in degree (viz. proportion of common to variable feature taken
up and accentuated) from particular or concrete images. And so long
as they remain merely pictorial _images_, there seems no reason to
attribute to them any general function or import.
[105] Cf. Taine, _On Intelligence_, Part i, Book ii, Ch. 2.
The true process of conception, as generalisation or general ideation,
that is a conscious representation of something as common to many as
distinguished from one, involves the active processes of thought,
analysis and synthesis, abstraction and comparison. It is only when
the child begins consciously to break up its images to mark off this
element or feature from that, and by help of such analysis discerns
and demarcates common features that general thought properly so
called, appears. In this way it reaches a distinct idea at once of an
individual thing and of general or common aspects among individuals. We
have now to examine into this true thought-process.
_Transition to Conception Proper._—The transition from merely
imagining to thinking proper is effected by processes of reflective
attention in which abstraction and comparison play a chief part. In
order to understand how this occurs we may suppose the process of
automatic assimilation checked by the introduction of some impressive
difference. Thus a child proceeds to play with a visitor's dog and
finds it wanting in the friendly sentiments of his own pet. Here
difference which, in the earlier stage of automatic assimilation,
remained indistinct in the background of consciousness, is brought
forward. The unlikeness of _morale_ in spite of the likeness of
_physique_ is forced on his attention, the present percept is separated
from and opposed to the image, and a step is taken in marking off
likeness from surrounding difference.
As differences thus come into distinct view and impress themselves
on the mind as the constant accompaniment of likenesses, a new and
explicit grasp of likeness-in-difference ensues. This starts from a
mental separation of the several perceptual constituents of the generic
image, and a reflective comparison of these one with another, so as
to demarcate common features or likenesses from peculiar features or
unlikeness. Such comparison, or series of comparisons, begins with
incomplete analysis and vague apprehension of likeness and ends in a
more complete analysis and more definite apprehension of likeness. In
this way, for example, the child waking up to differences among apples,
goes back on his various experiences, and by noticing and setting aside
variability of taste, size, etc., gets a clear grasp of the common
essential features. Such a conscious active separation of definite
points of resemblance from among a confusing mass of difference is what
psychologists and logicians more especially mean by Abstraction.
_Differentiation of Notions of Individual and Class._—As was pointed
out just now the coexistence of likeness with unlikeness in the child's
experience, may mean one of two things, viz. persistence or identity
of one individual object, in spite of certain changes, or a general
similarity among a number of different individuals. The process of
conception is sometimes described as if the child started with a
definite knowledge of individuals and then proceeded to generalise or
form a class-idea. There is, however, every reason for saying that
the two modes of interpreting likeness-in-difference are reached
concurrently and by processes largely similar. Thus it seems most
reasonable to suppose that the baby which 'da-das' every bearded person
it sees is as yet clearly conscious neither of individuality nor of
generality. In other words we must not assume that it is stupidly
confounding its sire with a stranger, or, on the other hand, forming
an idea of a general class. At this stage the child merely recognises
certain interesting similarities and proceeds to express the fact. We
have to suppose that the clear apprehension of individual sameness
is reached but slowly and in close connection with the first clear
consciousness of different things attached by a bond of likeness.
To say that the child's knowledge begins with the concrete individual
is not to say that it attains a clear consciousness of what we mean by
an individual thing persisting and the same (in spite of change) before
it begins to generalise. We must remember that the cognition of a thing
as persistent and continuous is the result of lengthy and complex
processes of comparative reflection. To individualise is thus to think
just as to generalise is to think.[106] In truth, the psychological
development of the idea of individuality proceeds along with that of
generality, each being grasped as a different way of interpreting
partial similarity among our percepts.[107]
[106] Hence the logician can speak of the idea answering to a
proper name as a singular _concept_. See Lotze, _Logic_, p. 34.
[107] The question of the priority in the individual of
the knowledge of the individual or of the general class,
the question known as the _primum cognitum_ has been much
discussed in connection with the linguistic problem whether
names are first used as proper names or as general names.
_The Process of Generalisation._—When once this differentiation of
the individual idea from the class idea has advanced far enough the
process of generalisation proper, or the grasp of common or general
qualities, is able to be carried out in the way usually described
by psychologists. That is to say, a number of individual things,
represented as such, are now compared, the attention withdrawn by a
volitional effort, from points of difference and concentrated on points
of likeness (abstraction) and so a true process of generalisation
carried out.
The common account of the process of conception here followed, as a
sequence of three stages, Comparison, Abstraction, and Generalisation,
rather describes the ideal form of the process as required by logic
than the mental process actually carried out. As we saw above a vague
analysis or abstraction precedes that methodical comparison of things
by which the abstraction becomes precise and perfect, that is to say,
definite points of likeness (or unlikeness) are detected. With regard
to generalisation it has been pointed out that a rudimentary form of
this process is involved in abstraction. To see the roundness of the
ball is vaguely and implicitly to assimilate the ball to other round
objects. It is to be added that an imperfect grasp of general features
as such (commonly) precedes the methodical process here described.
The child realises in a measure, the general function of the name
'horse' before he carries out a careful comparative analysis of the
horse-characters. At the same time the use of the word generalisation
is important, as marking off the clear mental grasp of the class-idea
as such, that is the idea of an indeterminate number, of objects, known
and unknown, answering to a certain description.[108]