186

CHAP. IV.
SECT. VII.

Abstraction described.

SECTION VII.

REPRESENTATION OF ABSTRACTIONS.

§ 123. It is frequently necessary to withdraw the mind from some of the qualities of objects for the purpose of giving undivided attention to others. This process is called abstraction. The quality or qualities to which attention is given are properly said to be prescinded from the others; the mind is properly said to be abstracted from the qualities to which attention is not given. In ordinary usage, however, this distinction is not attended to, and the quality singled out for special attention is said to be abstracted from the others, and is usually called an abstraction. There may be abstraction from individual objects of perception, as where the colour or the figure of an object is attended to apart from its other qualities. And we have now to consider how the representative faculty operates with reference to these abstractions.

§ 124. Considering first the qualities of a body which correspond to special sensations, we observe that the representation can be effected only by the help of the special organ of sensation concerned in the Represen- original intuition. A colour can only be represented in connection with the eye; a smell in connection with the nose; and so on. Thus, by the aid of the organs of sense, a representation may be made of particular qualities abstracted from an object. But

tation of

abstract sensations.

there is a series of so-called qualities, consisting of
extension, figure, position, and other modes of space,
which must not be confounded with those qualities
that are the correlatives of sensations. Qualities
that are the correlatives of sensations are represented
by the aid of the one special sense-organ with
which they are peculiarly connected. Extension
may be represented in connection with any sensa-
tion located anywhere in the sensorium, but notably
in connection with the sensations of colour and
the tactual sensation. It is to be observed, further,
that the connection in representation between the
phantasms of colour and touch on the one hand, and
the idea of extension on the other, is inseparable. It
is impossible to represent a colour or a tactual
sensation except as occupying some form of space.
And in so far as any sensation is specially located
in any part of the sensorium, the same inseparable
connection with some form of space is found to exist.
We conclude, then, that we are able to represent the
qualities of bodies which correspond to our sensa-
tions apart from one another; that we can make
abstraction of the colour, or the smell, or the hard-
ness, or the taste of an object, and represent any-
one of them apart from the others. But when we
attempt to represent colour or hardness we are com-
pelled to join some form of extension with them;
there is such an inseparable connection between the
two that a separation, even in thought, is impossible.
§ 125. Let us consider now the
representation of extension or space.

nature of our

Extension or

CHAP. IV.

SECT. VII.

CHAP. IV.

SECT, VII.

Of space or extension.

space, considered apart from the objects which occupy it, is undoubtedly an abstraction. Extension, we have seen, is the form of which the colour, hardness, and other qualities of bodies are the matter. And the question arises, whether we can represent the form apart from the matter; we have already seen that we cannot represent the matter apart from the form, and a little reflection will convince us that the reverse is equally true. The representation of pure space, or pure empty extension, is an impossibility. For when we attempt to represent space, we invariably do so by thinking of the possibility of moving through it. We think that, no matter how far we travel through space, there is still a possibility of going farther. And if we attempt to conceive a limited portion of space we must do so by connecting it with some sensible boundary, or some collections of qualities, or some possibilities of motion. This impossibility of representing pure space apart from the idea of some qualities occupying it, or some objects moving through it, might be inferred from the nature of our conception of space. It is an abstract formed from particular relations of extension. But extension is the form of intuition, the form in which objective phenomena are perceived. But the form of phenomena is not itself a phenomenon, and we therefore need not expect it to be capable of being represented as one. The doctrine which we have maintained regarding our representation of space does not affect the question as to the nature of its actual objective existence. That is a question which belongs rather to

metaphysics than psychology, and which, therefore, CHAP IV. we shall not at present discuss.

SECT. VII.

abstrac

tions.

§ 126. In considering the possibility of represent- Logical ing logical abstractions, we must anticipate a little, and suppose the reader to be familiar with the nature of the process to be afterwards described. The great majority of the words in every language are the names of classes of objects-as man, triangle, tree, river; and the question we have at present to consider is, how, if at all, can we represent to our minds the objects indicated by words such as these? And it must be remembered that there are in nature no things corresponding to these general names. There are plenty of individual men, tall or short, black, white, brown, or olive; but there is no such thing as man in general as distinguished from particular individuals. So there are triangles equilateral, scalene, right-angled, and so on; but triangle in general is unknown. A little reflection will show not only that such a thing as man in general does not exist in nature, but that it is incapable of being represented to the imagination. For if we attempt to represent what we mean by man to our mind, we shall find the representation assuming some particular form, and colour, and other qualities. We cannot help it. And in the same way of all other names which indicate classes of objects. It is impossible to represent the connotation of a general name, as for example, triangularity, without bringing in along with it, more or less definitely, the other qualities or parts belonging to some particular objects of the class.

CHAP. IV. SECT. VII.

Difficulty

obviated.

§ 127. It may be asked, then, how are we able to understand the definition of a class of objects, as, for

stated and example-A triangle is a figure bounded by three lines? Into the definition there are not introduced any peculiarities belonging to particular triangles, and yet we are able to understand its meaning. The explanation of this is probably to be found in the relation between language and the object of thought. When a word has become attached to a particular object or class of objects, it may frequently be used without bringing into the mind the things denoted by it. And especially when words have become very familiar, they are joined together in propositions, and the propositions are assented to, although there is in the mind no attempt to realise their meaning. Thus a familiar proposition, such as, A triangle is a threesided figure, is listened to; it has been thoroughly understood long ago, and deposited in the memory as something to be received without question; and, consequently, when the proposition is pronounced it excites no mental activity except a vague belief that it is quite correct. But if an attempt be made to realise a general name, or to understand a proposition in which a general name is the subject, there must be a representation of a more or less complete and definite object.

§ 128. The employment of words indicating classes, or general qualities, or general modes of action, as if they represented real things, has led to many erroneous conclusions. And, consequently, it is important that words and propositions should be