extreme, by showing the utter falsity of the ideal theory. He took the ground that the existence of any such representative images in the mind is wholly without proof, nay more, is inconceivable; that while we can conceive of an image of form or figure, we cannot conceive of an image of sound, or of taste or smell. The hypothesis is wholly without foundation. But even if it were conceivable and established by sufficient evidence, still it would explain nothing as to the manner in which the mind perceives external objects. It relieves no difficulty. If the representative image be itself material, how can the mind take cognizance of it? If not material, how can it represent matter, and how can the mind know that it does represent correctly the external object?
State of the Matter since Reid.—Since the time of Dr. Reid, this theory of representative perception, at least in this non-egoistic form, has been for the most part abandoned, and philosophers have been content to take the ground indicated by consciousness, and the common sense of mankind, that in perception we take direct cognizance of the external object.
Position of Hamilton.—It remained for Sir W. Hamilton to complete the work which Dr. Reid began, by showing that the representative theory, in its finer or egoistic form, as held by Dr. Brown and others, is equally untenable or unsound; that it makes little difference whether we regard the image or idea, which we take to represent the external object, as something distinct from the mind itself, or whether we view it as a mere modification or state of the mind, so long as we make any thing of the sort the direct object of perception instead of the real external thing. Idealism is the result in either case, and philosophical skepticism the goal. In place of any and all such views, Hamilton maintains, with great power and earnestness, the doctrine of natural realism—that in perception we are cognizant immediately and directly of the external object.
As no other writer has so fully elaborated this department of science, it may be of service to present in this connection the chief points of his theory.
Chief Points of Hamilton's Theory of Perception.—All perception is immediate cognition; we perceive only what we apprehend as now and here existent; and hence what we perceive is either in our own organism, viewed as material, extended, etc., or else is in immediate correlation to it. The organism is, in perception, viewed as not-me; in sensation, as of the me.
What is given in Perception proper.—What we apprehend in perception proper is: 1. The primary qualities of body as pertaining to our own organism; 2. The secundo-primary qualities of bodies in correlation to it. (See Hamilton's division of qualities of bodies, as above.)
Primary Qualities of external Objects, how known.—The primary qualities of things external to our organism we do not perceive immediately, but only infer, from the effects produced on us by them. Neither in perception nor sensation do we apprehend immediately, or in itself, the external cause of our affection or sensation. That is always unknown to consciousness, known only by inference or conjecture.
External Existence, how learned.—The existence of the world without is apprehended not in a perception of the primary qualities of things external, but of the secundo-primary—i. e., in the consciousness that our movements are resisted by something external to our organism. This involves the consciousness of something external, resisting. The two things are conjunctly apprehended.
This presupposes what.—This experience presupposes the notion of space, and motion in space. These are inherent, instinctive native elements of thought, and it is idle to inquire how we come by them. Every perception of sensations out of, and distinct from, other sensations gives occasion for conceiving the idea of space. Outness involves it.
Points of Difference between this Theory and Reid's.—The system, as thus stated, differs in some respects materially from the doctrine of perception advanced by Dr. Reid, and generally adopted since his time by the English and Scotch philosophers. According to Hamilton, perception is not, as held by Reid and others, the conception of an object suggested by sensation, but the direct cognition of something. We do not merely conceive of the object as existing, and believe it to exist, we know it and perceive it to exist. Nor does sensation precede, and perception follow, as generally stated, but the two are, in time, conjunct, coëxistent. Nor do we perceive the secondary qualities of bodies, as such, but only infer them from our sensations. Neither do we perceive distant objects through a medium, as usually held, but what we perceive is either the organism itself, as affected thus and thus, or what is directly in contact with it, as affecting and resisting it. Extension and externality, again, are not first learned by touch, as Reid holds, and most subsequent writers, both English and American, but in other ways; the former, by the perception of the primary qualities of our own organism, as the seat of sensations distinct from other sensations elsewhere localized; the latter, by the resistance which we experience to our own locomotive force. Finally, sensation proper is not, as with Reid and others, an affection purely of the mind, but of mind and body as complex. Its subject is as much one as the other.
INTELLECTUAL FACULTIES.
PART SECOND
THE
REPRESENTATIVE POWER
GENERAL OBSERVATIONS.
Nature of this Power—Its various Forms.—It is in the mind's power to conceive or represent to itself an object not at the time present to the senses. This may take place in several forms. There may be the simple reproduction in thought of the absent object of sense. There may be, along with the reproduction or recurrence of the object, the recognition of it as a former object of sensation or perception. There may be the reproduction of the object not as it is, or was, when formerly perceived, but with variations, the different elements arranged and combined not according to the actual and original, but according to the mind's own ideals, and at its will. This latter form of conception is what is usually termed imagination—while the general term memory, as ordinarily employed, is made to include the two former. While using the term in this general sense, we may properly distinguish, however, between mental reproduction, and mental recognition, the latter being strictly the office of memory.
All these are but so many forms of the representative power. We may designate them respectively as the reproductive, recognitive, and creative faculties. The mind's activity is essentially the same under each of these forms. The object is not given but thought, not presented to sense, but represented to the mind. The process is reflective rather than intuitive. It is a matter of understanding rather than of sense or of reason. It is a conception, not a perception or an intuition, and it is a simple conception of the object as it is or is conceived to be, in itself considered, and not in relation to other objects.
CHAPTER I.
MEMORY.
§ I.—Mental Reproduction.
I. Nature of the Process.
General Character.—As now defined, this is that form of mental activity in which the mind's former perceptions and sensations are reproduced in thought. The external objects are no longer present—the original sensations and perceptions have vanished—but by the mind's own power are reproduced to thought, giving, as it were, a representation or image of
