way conditioned on impressions from without, it is impossible to believe that they could exercise that power if entirely separated from the object and from all means of communication with it. We reject Reid's doctrine of the immediate perception of the distant as being contrary both to fact and reason.

Original and

The teaching of this philosopher respecting original acquired per- sense-perception is not so objectionable as that which ception as we have just considered, and which pertains to acdistinguished by Reid. An quired perception only. His account of original perimportant ception is defective rather in the mode of its conception distinction. and expression than in the principal matter presented.

Believing every act of cognition to be of a purely internal origin, and not, like sensation, the effect of external causes, he was led to say that perception is a kind of suggestion, or inference, made by the mind on the occasion of its sensations. Nevertheless, he held this to be an act of immediate cognition, because it is entirely independent of any past knowledge or perception of things, and itself originates both our conception of objects and our belief in their existence. Therefore, also, it is radically different from that suggestional, or inferential, cognition which it is the province of the reasoning faculty to supply.

Reid's doctrine of the immediateness of both original and acquired perception may be best gathered from a passage in his second essay. "In perception," he says, "whether original or acquired, there is something which may be called the sign, and something which is signified to us, or brought to our knowledge, by that sign. In original perception the signs are the various sensations which are produced by the impressions made upon our organs. The things signified are the objects perceived in consequence of those sensations, by the original constitution of our nature. Thus, when I grasp an ivory ball in my hand, I have a certain sensation of touch. Although this sensation be in the mind, and have no similitude to anything material, yet, by the laws of my constitution, it is immediately followed by the conception and belief that there is in my hand a hard smooth body of a spherical figure, and about an inch and a half in diameter. This belief is grounded neither upon reasoning nor upon experience; it is the immediate effect of my constitution; and this I call original perception.

"In acquired perception the sign may be either a sensation or something originally perceived. The thing signified is something which, by experience, has been found connected with that sign. Thus, when the ivory ball is placed before my eye, I perceive by sight what I before perceived by touch, that the ball is smooth, spherical, and of such a diameter and at such a dis

tance from the eye; and to this is added the perception of its color. All these things I perceive by sight, distinctly and with certainty. Yet it is certain, from principles of philosophy, that if I had not been accustomed to compare the informations of sight with those of touch, I should not have perceived these things by sight. I should have perceived a circular object, having its color gradually more faint towards the shaded side; but I should not have perceived it to have three dimensions, to be spherical, to be of such linear magnitude, and at such a distance from the eye. That these last-mentioned are not original perceptions of sight, but acquired by experience, is sufficiently evident from the principles of optics, and from the art of painters, in painting objects of three dimensions upon a plane which has only two. And it has been put beyond all doubt by observations recorded of several persons who, having, by cataracts in their eyes, been deprived of sight from their infancy, have been couched and made to see after they came to years of understanding. . . . This power, which we acquire, of perceiving things by our senses which originally we should not have perceived, is not the effect of any reasoning on our part; it is the result of our constitution and of the situations in which we happen to be placed."

In the foregoing the word "sign," as applied to a sensation, is used in a peculiar sense. It indicates that the sensation, when experienced, is the occasion of a knowledge which yet results immediately from the constitution of the soul, and which therefore is not at all an inference from past knowl edge. It is also to be noticed that an original perception, or the sensation appropriate to it, becomes the sign for an acquired perception in precisely the same manner that a sensation is the sign for the original perception itself. Although the power of acquired perception is obtained in the course of one's experience, this perception is not of the nature of reasoning; it is not an inference, properly so called, but the direct result of our constitution as modified during the past experience. In the passage immediately subsequent to that just quoted, Reid goes on to argue this point at length.

The inferen

ception.

3. The doctrine of acquired perception, thus pretial nature of sented, has not been accepted as a final statement. acquired per- Before the time of Reid, Bishop Berkeley, in his "New Pres. Porter Theory of Vision," had skilfully analyzed our sightperceptions of the distance and size of objects, and had shown them to be judgments in which ascertained standards of measurement are easily and unconsciously employed. Possibly the reasonings of Berkeley suggested to Reid the necessity of

quoted.

distinguishing our original from our acquired perceptions; they certainly indicated and determined the direction in which later philosophy has advanced. During the present century the action of the reasoning power has been shown to be much more pervading than was formerly supposed; and at the time of our writing there is a general agreement that acquired perception is an inference, nay, that it is an inference founded on induction.

In illustration of this we cite the following characteristically judicious remarks of President Porter. "It may surprise many," he says, "to learn that the processes employed in the acquired perceptions are processes of induction. Induction is usually conceived and described as a process which is appropriated to philosophical discovery, which requires wide generalization and profound reflection, and issues only in comprehensive principles and laws. A little reflection will satisfy any one, however, that the act of mind is the same with that performed in every one of the acquired perceptions. The difference between the two kinds of induction is not in the process, but in the materials upon and with which the mind performs them. But the acts, the fundamental assumptions, and the liability to error in both, are essentially the same."

Re

Were we to add anything to these words, it would be simply to emphasize the statement that the circumstances of the origin and development of our inferential perceptions cause them to differ greatly from the formal operations of the reasoning power. In particular, the processes involved in them are so simple, and become so habitual, and take place so easily and quickly, that they escape from all ordinary analysis. To understand them. requires special methods of observation and comparison. This distinction between our articulate reasonings and the instantaneous conclusions of perception should be fully recognized. The doctrine Reid's doctrine of original perception may be acof original cepted as substantially expressing the truth. perfected by jecting both representative ideas and reasoning of ilton. Ham- any kind, it is truly a theory of immediate cognition. ilton quoted. This immediateness is somewhat marred when perception is made the interpretation of a sign, or the belief suggested by an experienced sensation. Even while the interpretation or suggestion introduces a cognition which is independent of past knowledge, this cognition is represented as subsequent in time. to the sensation upon which it depends, and seems to be separated by the sensation from the object perceived. There is reason for saying that the object is perceived through, or by means of, the perception of the sensation, and not simply along with, this

perception

Sir W. Ham

66

66

latter perception. Such a mode of statement is an invitation easily accepted by a thinker of Kantian proclivities to question the authority of the suggestions" of the mind, in regard to objects external to the soul; it also gives one who supposes the interpretation" mentioned to be an ordinary logical inference the opportunity of showing that there is no ground for any such inference, nay, that an original inferential perception is an absurdity. The latter objection is unjust, being grounded on misapprehension; the former may be partially met by saying that what is ultimate and irresistibly self-evident should be received as its own proof; yet both naturally present themselves.

The discussion of difficulties like these led to the inquiry whether the doctrine of the Glasgow professor was not capable of improvement. In particular, it was asked, "Have we not ground to believe in a perception yet more immediate than that which Reid describes?" and "May not the phenomena of such perception be set forth in terms more exactly expressive of its nature than any which have yet been used?" The answer to these questions was wrought out by Sir William Hamilton, and is the principal addition which his learned and laborious criticism has made to the philosophy of Scotland. His improvement of the doctrine of perception pertains to two points.

In the first place, discarding the statement of Reid and his immediate successors, that "perception follows sensation," or that sensation is the antecedent of perception," Hamilton forcibly maintained that both the sensation and the senseaffecting object, together with the proper characteristics and relations of the latter, are perceived directly and at once, and in the same intellectual movement. And, secondly, he rejected all such terms as "interpretation" and "suggestion," and spoke of the intuitions and presentations of perception. "External perception, or perception, simply," says he, "is the faculty presentative, or intuitive, of the phenomena of the non-ego, or matter, if there be any intuitive apprehension of the non-ego at all. Internal perception, or self-consciousness, is the faculty presentative, or intuitive, of the phenomena of the ego, or mind."

By these simple changes, in which Reid himself would have heartily acquiesced, Hamilton freed the doctrine of perception from a liability to be misapprehended, and rendered it in every way conformable to the common judgment and experience of mankind.

The foregoing sketch indicates how slowly and with what difficulty a satisfactory theory of perception has been reached by speculators. The earliest philosophers regarded the soul

as a material essence, and its perceptions and thinkings as molecular motions resulting from the impact or attraction of external things. The membranous simulacra of Empedocles, constantly flying off from objects and entering through the avenues of sense, betoken a more thoughtful theorizer. Next we notice the obscure and half-developed views of Plato and Aristotle; the former of whom scarcely recognized any connection between thought and sense, and the latter of whom made perception the result of the combined action of the semi-corporeal sensitive soul and the immaterial rational mind. The sensible species of the schoolmen, produced by the percipient spirit, yet distinct from it, and the direct objects of cognition, may be taken as showing progress in the recognition of the intellectual character of perception. This progress is more apparent in the "ideas" of Occam, Descartes, Leibnitz, Arnauld, and Locke, which were identical with perceptions, yet the immediate objects of perception. These introduced the logical but self-destructive philosophies of Berkeley and Hume. Reid followed, denying that we perceive by representations, and teaching, though imperfectly, the doctrine of immediate perception. Finally, Sir William Hamilton expressed the truth by saying that our first cognition of things within, or in contact with, the sensorium is absolutely free from any process of inference, and that therefore it should be called presentative, or intuitive, perception.

CHAPTER XXXIV.

THE RELIABILITY OF PRESENTATIONAL COGNITION.

The reliabil

cognition.

The question

Augustine,

1. THE question as to the reliability, or truthfulness, ity of sense of the senses pertains chiefly to our original, or immediate, cognitions. Mistakes occur in acquired, or pertains to inferential, perception; but our original perceptions original perception chief- are never incorrect. The so-called deceptions of sense Anselm, are merely wrong conclusions from facts immediately and Aristotle perceived. This is the position of Reid in his chapquoted. ter on "The Fallacy of the Senses." In speaking of "the errors to which we are liable in our acquired perceptions," he even denies that such perceptions are those of sense at all. "Acquired perception," he says, "is not properly the testimony of those senses which God hath given us, but a conclusion