The sentient principle, in fact, suffers impression when unlike; but, having been impressed, it is converted into like, and becomes the same as that by which the impression is made.
Notes Layout 2 Note 1, p. 84. In our treatises upon action and impression, &c.] Some commentators have, in the treatises here alluded to, seen only a reference to other disquisitions, as those upon "'reproduction and destruction,' or decay," περὶ γενέσεως καὶ φθοράς; but as the passages which are cited do not meet the whole question, it has been suggested by Trendelenberg that the allusion may be to some other work which has not come down to us.
Note 2, p. 84. It is difficult to understand, &c.] In another chapter of this treatise, Aristotle has alluded to the power possessed by the senses of recalling former impressions; of realizing images at will, that is, without external objects. But the question here is to learn why the senses, which were supposed to be derived from the elements, from which or the accidents of which sensation itself was derived, are not in constant activity. The answer is, that the normal state, so to say, of the sensibility is potentiality, and that it is insusceptible, therefore, of perception, without impression by something from without to call it into action; just as the combustible material requires, in order to burn, the agency of fire. But the comparison contains a converse proposition, as while the material is required for the sensibility, it is fire, which may be regarded as the sensibility, which is required for the material.
Note 3, p. 84. Since we speak of sentient perception, &c.] These passages upon perception and sensation, which, in themselves, when deeply inquired into, are sufficiently obscure, are still less, if possible, apprehensible, on account of the wording and the attempted illustration by the leading terms, potentiality and reality. It is obvious, however, that we may and do speak of an individual as one who hears and sees, whether or not, at the moment, conscious of sound or colour; whether that is, awake or asleep, active or quiescent, in potentiality or reality. But an individual is, strictly speaking, only then seeing and hearing when he is actually sensible of colours and sounds; just as an individual, to use Aristotle's analogy, is only then to be accounted really learned, when actually reflecting upon and exercising some one special subject of knowledge. All attempts, however, to scrutinize the intimate operations, so to speak, of the sensibility under impression from without or excitation from within soon lose, even with the advanced knowledge of this age, the character of inductive science, and are lost, as in the text, in the maze of metaphysical abstractions. It seems to be the object of the argument to prove, that the sensibility, before being acted upon by external objects, such as light, sound, colour, &c., exists in potentiality and is unlike; when acted upon, it is raised to the state of reality, and thus made like to that by which the impression is made.
Note 4, p. 85. Before proceeding further let us, &c.] This and the following passages are but repetitions of what had been said, and further attempts at elucidation; they all too depend for a meaning upon the two great leading terms. For motion is in a two-fold state—when generated by impulse from without it is passive, when self-generated it is active; and that may be regarded as potential, this as real. Thus, if a body be at rest, before being impelled, the agent, by which it is impelled, is unlike and active; but, when so moved, it is, by the very act of motion, made active, and like to the agent.
Note 5, p. 85. But we must draw a distinction, &c.] These passages embody, in examples, the two terms so often alluded to, and exhibit the opposite conditions of human beings—every man is learned, potentially, because man is naturally so constituted as to be able to become learned, or, being learned, is subject to an eclipse of his learning by sleep, or disease, or inattention; and every man, endowed with the faculties of his nature, may acquire some one branch of learning, and, when there is no impediment to his doing so, by the exercise of that knowledge, become learned in reality.
The individual who is learned in the first sense cannot, without a succession of changes, (while passing, that is, from ignorance to knowledge), become, at will, learned, in reality; and he can, therefore, be accounted learned, only in potentiality.
Note 6, p. 86. The term impression, &c.] The same mode of illustration, through those two terms, is still continued—impression may be to an extent to destroy sensibility, and obliterate, of course, sensation, or it may be to that genial extent which raises, so to say, potentiality to reality, and renders the being conscious of external objects. So an individual, with knowledge yet potential, that is, possessed but not exercised, can, by reflecting upon it, without any change being wrought, render it a reality; for the possession of knowledge, like the endowment of sensibility, implies the self-same two-fold condition. Thus, the state of reflection is to acquired knowledge what external impressions are to sensibility; for, in either case, the agencies, when genial, occasion the transition from potentiality to reality; and so eliminate practical knowledge or perfect consciousness.
Note 7, p. 87. The first change, however, of this kind, &c.] It is not easy to perceive how this nascent condition can be a change, unless the first germ of being may be so regarded; and, indeed, it may be supposed, from the first moment, to have already, in potentiality, the powers which are yet to be developed. It may be, too, that this mysterious entity, along with the faculties and powers of its own nature, may involve the idiosyncrasy of the parent, for good or for ill; which was indeed exemplified in the life and death of the philosophical Montaigne. This capacity of the system for retaining dormant within it a something to be developed, by unknown causes, in time, is exemplified in the atom of virus, which, after an indefinite period, may, by mysterious agency, become a reality in the form of Hydrophobia. Well might the philosopher, when reflecting upon these incidents, exclaim, "Qui m'éclaircera de ce progrès, je le croirai d'autant d'autres miracles qu'il voudra."
Note 8, p. 86. So that the process by which an individual, &c.] This very obscure passage seems to intimate that, as instruction is only the development of faculties pre-existing and in potentiality, it is not to be regarded as an impression; for such an opinion would imply, instead of nature's ordinary process (development), a change from a privative state (ignorance), as well as change in habits of thought. This cannot, however, be insisted upon with much confidence; the French version is, "Done, ce qui fait passer l'être qui est en puissance à la realité parfaite, à l'entelechie, en fait d'intelligence et de pensée, doit s'appeller, non du nom d'apprentissage, mais d'un tout autre nom."
Note 9, p. 87. There is an analogy between, &c.] Sensation, that is, is to the body what reflection is to the mind, save that the one is produced by impression from without, and, therefore, not subject to the will, while the latter is the operation of will upon internal faculties. Thus, sensation admits a series of individual impressions which are to be analyzed and compared by the mental operation; and as the former becomes the parent of inductive, the latter is the source of deductive science.
Note 10, p. 88. Let it for the present suffice, &c.] An obvious distinction of potentiality—a boy is, potentially, qualified to be a general; that is, he has, by nature, faculties and powers which, when developed, will fit him for the office; and so is one who, although of suitable age, and whose faculties and powers are developed, may not yet have acquired the necessary military knowledge. An analogous distinction may be traced in sentient properties, but it is too evanescent for precise description; and the closing paragraph is a kind of summary of the conversion of the potential and unlike into the real and like.
Prelude to Chapter VI.
This chapter, adopting a former suggestion, commences with the nature and influences of the objects and properties which act upon the senses. As those properties or influences, however, whatever their denomination, light, sound, odour, savour, motion, number &c., are considered in their relation to the senses, respectively, they here are merely characterized under the terms, which are defined, of peculiar and common. Casual or chance perception is exemplified by a figure which is far from being apparent.
Chapter VI.
Chapter VI.
Let us, before proceeding further, speak upon the objects of perception in relation to each of the senses. The object of perception is spoken of in a three-fold manner, as there are two ways in which we speak of perceiving objects distinctly, and one in which we speak of perceiving them accidentally; and of those two ways one signifies the property which is peculiar to each sense, and the other the property which is common to all the senses. I mean by peculiar property that which cannot be perceived by any other than its own sense, and concerning which that sense cannot be deceived—as colour for sight, sound for hearing, and savour for taste. The touch, indeed, discriminates several differences of quality, but every other sense distinguishes only its own subjects; and thus sight or hearing is never deceived as to whether it is colour or sound which is seen or heard, although it may be deceived as to what or where the coloured, what or where the sonorous body may be.
Such then the properties which are said to be peculiar and to belong to particular senses; but there are properties, such as motion, rest, number, form and magnitude, which are termed common, as they belong not to any one sense, but to all in common. Thus, there is a movement which is perceptible both by Touch and Sight. An object is said to be perceived accidentally when, for example, something white may be the Son of Diares—for the percipient is sensible of the individual accidentally, because of his being an accident of that which is perceived; and, therefore, no impression is made by that which is perceived, as a special object, upon the percipient.
The properties of bodies, which are in themselves perceptible, are, strictly speaking, peculiar properties; and to such each particular sense is naturally and essentially related.
Notes Layout 2 Note 1, p. 90. The Touch indeed, &c.] This sense has a wider range of perception than any other that is, it is not restricted, like the Sight, Hearing, and Smell, to a definite organism and one mode of impression; and, besides being extended over the body, it is essential to animal existence. The text makes no allusion to the Taste, because this sense was regarded as subsidiary to or a modification of the Touch. The special senses are Sight, Hearing, and Smell; Taste is less definite, as the tongue is sensible of tangible as well as sapid qualities; and Touch is extended over the body. Some properties, however, which are enumerated, are subject to all the senses, and, hence, termed common; but the attempted illustration of them by "a kind of motion" (κίνησις τις) does not, owing to its vagueness, assist in explaining them.
Note 2, p. 91. An object is said to be perceived, &c.] An example in illustration of casual or accidental perception; but it is by its wording so obscure as to stand itself in need of elucidation. The purport, however, seems to be, that the percipient does not, by sight, (as sight distinguishes only colour and form) discern what the white object really is; but the other senses, by some accidental perception, coming in aid of the special sense, may determine that the white object is a certain individual. There may besides, perhaps, be a covert allusion to the two-fold acceptation of the term accident, which signified then as it does now both casual incidents and the real, or inalienable properties of bodies; and if so, the passage may imply that the individual is perceived by chance; detected, that is, by a mere guess. It is of little moment, but the individual alluded to is said, by Philoponus, to have been a friend of Aristotle's; and that letters which had passed between them were extant in his time.
PRELUDE TO CHAPTER VII.
The treatise commences the examination of the senses with the Sight, and closes with the Touch, which is somewhat contrary to Aristotle’s estimate of their relative importance; for he has shewn that the Touch is the first, as it is the most universal of all the senses, as well as essential to animal existence. Thus, this sense is to sentient creatures what nutrition is to other beings; for as without Touch there can be no animal, so without nutrition there can be no life. Descartes, more in accordance with Aristotle’s teaching, begins with the Touch, and then proceeds to the Taste, Smell, Hearing and Sight; and so Grant makes “all the other senses to be but modifications of the Touch.” Cuvier, however, reverses this it may be general order, and treats of the special senses before the Touch. It may be well to observe, that the senses as well as their modes of excitation, had been treated of in a distinct work, which may be regarded as supplementary to the present treatise; and this will explain why the eye and vision are here very briefly alluded to, while particular attention has there been given to the ear and hearing.
Chapter VII.
The visible is that for which vision is the sense, and the visible is both colour and something which is describable by words, although it happens to be without a name; but our meaning will become clear to those who accompany us in the inquiry. The visible is colour, and colour is that which is upon something visible in itself; and this something is visible, not only after its appellation but, because it has in itself the cause of being visible. All colour is motive of the diaphanous, in activity, and to be so motive is the nature of colour. On which account nothing is visible without light, but the colour of each object is visible in the light; and we must, therefore, first say what light is. There is a something diaphanous, and I call diaphanous what is visible, and yet not visible, strictly speaking, in itself, but made visible by colour, which is foreign to it. Such is air, and water, and many solid bodies; yet neither air nor water, as air or water, is diaphanous, but the same nature is present in both those elements, which is in the eternal supernal body. Light is the active state of that same diaphanous, in so far as it is diaphanous, and darkness is the same in its state of potentiality. But light is the colour, as it were, of the diaphanous, when made diaphanous in reality by fire, or other such element as the supernal body; for to it belongs a something which is identical with fire. We have thus said what is the diaphanous and what light, and have shewn that neither of them is fire, nor a body, strictly speaking, nor an emanation from a body, (as, in that case, they would be corporeal), but that they are the presence in the diaphanous of fire or something analogous to fire, since two bodies cannot possibly coexist in one and the same body.
Light seems to be the opposite to darkness; and as darkness is the absence of a particular state of the diaphanous, it is evident that the presence of that state must be light.
Thus Empedocles, or whoever else may have held the same opinion, was wrong in supposing that light was transported and manifested, without our consciousness, between the Earth and surrounding space; for the opinion is opposed as well to sound conclusion as to observation of the phenomenon. If the interval were small, the fact might, indeed, escape us; but, extended as it is from the East to the West, the postulate is too extravagant to be admitted.
Now that which is without colour is receptive of colour, as that which is without sound is receptive of sound; and that which is without colour is the diaphanous and the invisible or scarcely visible, such as darkness seems to be. Such too is the diaphanous; but then it is the diaphanous, not in potentiality but, in reality; for the same nature is sometimes darkness and sometimes light. But all objects are not visible in light, as there are some of which the peculiar colour only of each is visible; for some, not visible in light, produce sensation in the dark, as certain fiery brilliant appearances (which have no special appellation,) which emanate from fungi, horn, scales and eyes of fishes, but the peculiar colour is not seen of any one of those objects. It is foreign to our present purpose to explain how such objects become visible; but this much is manifest, that it is colour which is visible in light. Therefore, without light colour is not visible; for it is an essential property of colour to be motive of the diaphanous in activity, and the reality of the diaphanous is light. As proof of this, if any coloured object be placed over the sight, the object will not be seen, and yet there is colour, which is motive of the diaphanous, the air, that is, and, by its being continuous between the object and the sense, it is able to give motion to the visual organ. Thus, Democritus was wrong in thinking that if the medium were a void, vision would be so accurate as to render an ant visible in the sky. The opinion, in fact, involves an impossibility; for vision is produced by some kind of impression upon the visual organ, and as this cannot possibly be effected by the colour which is visible, there remains only that it must be by the medium, and thus a medium there must be; so that if there were a void, vision would be, not to say inaccurate but, altogether precluded.
It has thus then been said why colour must be visible in the light; but fire is visible both in darkness and in light, and necessarily so, since it is by fire that the diaphanous becomes diaphanous. The same reasoning holds good for sound and for odour, as nothing sonorous or odorous can produce sensation when in immediate contact with the sentient organ; but by odour or sound the medium is set in motion, and by it the organ is moved. Thus, when any thing sonorous or odorous is placed immediately upon the sentient organ, no sensation is given out; and this is the case with the sense of Touch, although less evidently so; but the cause of this shall be explained hereafter. The air is the medium for sounds, while that for odour has no special appellation, for there is a particular impression common to air and water; and what the diaphanous is to colour that which is in those elements is to odorous bodies, as aquatic animals appear to be sensible of odours. But neither man nor animals which breathe can smell without inspiring; and the cause of this shall be spoken of hereafter.
Notes Layout 2 Notes Layout 2 Note 1, p. 93. The visible is colour, &c] Aristotle says that the faculty of Sight announces to us, distinguishes, that is, the manifold and various shades of colours, on account of all bodies partaking of colour, and thus by Sight, especially, we are able to perceive common properties, such as form, magnitude, motion and number; but the Hearing, on the contrary, is perceptive only of distinctions of sounds from sonorous bodies and the variations of voice from such as have speech. The sense of "Hearing, however, contributes more than any other, since speech is the channel for instruction, to the cultivation of the understanding."
Note 2, p. 93. All colour is motive of the diaphanous, &c.] These passages seem almost to indicate a presentiment of the modern or undulatory theory of light, for they assume the existence of a diaphanous, that is, a subtle medium which, by its motion, is creative of vision. So too, the modern theory assumes a subtle elastic ether, which has inertia without gravity, which fills space, permeates all bodies, and admits of being set in motion by the agitation of the particles of ponderable matter, and which particles, when set in motion, communicating a like motion to the molecules adjacent, act upon others, and thus motion is propagated further and further in all directions. The theory of Aristotle is much the same— there is a diaphanous medium which may well represent the subtle ether, and which, when potential, that is quiescent, is darkness, and when set in motion by colour, (the property of which is to render it motive), is light, renders objects visible, that is. Thus, the same diaphaneity when passive, that is, potential, is darkness, when active, that is, in reality, is light, and the cause of objects being visible. The value of the hypothesis is diminished by the identification of the "diaphaneity" with air and water and solid bodies, because of their affinity with the supernal region or firmament above, which, together with all the heavenly bodies, was supposed to be of igneous nature; and to be corporeal, circular, and in constant motion.
Note 3, p. 94. Light is the active state, &c.] The diaphaneity which, when passive, is darkness, when set in motion and made active, is light, is made visible, that is; and thus light, being a mere condition of the diaphaneity, "is not a body, for, were it so, there would be two bodies in one, which is an impossibility." It may now seem strange that Aristotle should have paid so little attention to the opinion of Empedocles, "that light arrives midway from the sun, before it reaches the sight, or the earth;" for although it differed from his own, in regarding the sun as the source of light and the distinction of day from night, yet, in transmitted light, it supplied a motor, which was required for the completion of his own theory of sensation through the agency of a medium acted upon by impulsion.
Note 4, p. 95. Now that which is without colour, &c.] The diaphaneity, that is, when passive, is receptive of colour and made active, just as the air, when quite still, is more readily set in motion and made sonorous by percussion; and this leads, amid some confusion of thought, to the consideration of those luminous appearances (ignes fatui) which are visible only in the dark, by their colour. 'The precise nature of these appearances is still only conjectural, notwithstanding the advance of chymistry; but they are supposed to be due to phosphyretted hydrogen eliminated, under favouring circumstances, from decaying animal and vegetable matter, and ignited by contact with the atmosphere."
Note 5, p. 95. Therefore, witliout light colour is not visible.] Colour, that is, by imparting motion to the diaphaneity, renders it, from being potential and dark, actual and visible, that is, light; and thus, as without light there is no colour, so without colour there is no light; and this lends support to the opinion, that the air, as being a diaphanous medium, is essential to sight. Aristotle had indeed maintained, in opposition to Empedocles and others, that vision is not caused by the emanation of luminous rays from the eye as light proceeds from a torch or lamp; and he ridiculed the notion that vision is precluded in the dark owing to the extinction of those rays therein. It is probable that this theory first led him to adopt a medium and its successive motion, as the immediate cause of vision; as he had accounted for hearing by the propagation of the impulse given to the air by the sonorous body. Aristotle was unacquainted with the structure of the eye; but he was aware, of course, that it contains humours, and these he held to be necessary, not as being aqueous that is elementary but, as being diaphanous, for this property seemed to be as requisite for vision within the eye, as it is for the transmission of light to the eye. It was this assumed succession of action, after impression upon a diaphanous medium, which led to the conclusion that the eye itself must be diaphanous, and, therefore, that the visual power must be somewhere on the inside of the eye; and this is the only approximation to a right knowledge of the retina and its relations.
Note 6, p. 96. It has thus then been said, &c.] The cause of colour being visible is sufficiently obvious from what has been said; but fire was said to be visible both in darkness and in light, owing to its being, as fire, of the nature of the firmament above, which was believed to be fire, or something identical with fire. It may be presumed that the subject was here introduced, in order to notice and account for those luminous appearances, which have been alluded to, and which, in that age, could not but have been topics of wonder and speculation; they were irreconcilable besides, with the prevailing notions of colour and light.
Note 7, p. 96. The air is the medium for sounds, &c.] The air was by Aristotle held to be essential to sound; but it is not apparent why odour was supposed to be transmitted by some modified condition of air or water, unless, indeed, it was required in order to account for the perception of odours by fishes and aquatic animals. There was a difficulty, in fact, in accounting for the transmission of odour through air and water, because odour was held to be a vaporous exhalation eliminated by fire; and the "special organ of smell was said to be located about the brain," the coldest of all parts of the body, in order that the exhalation might there be condensed and made productive of smell. Thus, it might seem to be irreconcilable with odour, that it should be transmissible in air or water, and this may have led to the hypothesis of a modified condition of the elements for smell.
Note 8, p. 97. But neither man nor animals which breathe, &c.] The term in the text (ἀνάπνει), like our own term breathing, is expressive both of inspiration and expiration, whereas it is evident that the sense of the passage requires the former process only. And yet elsewhere, Aristotle, in his criticism of the theory adopted by Diogenes and Anaxagoras to account for the respiration of fishes, has clearly distinguished the one from the other. He objected also to Timæus and some others who had maintained that expiration must precede the other. Enough, however, that he perceived, although unacquainted with the parts on which odours impinge, or the organ by which they are made sensible, that they could gain access to the sense only through inspiration.
Prelude to Chapter VIII.
This chapter is upon sound and hearing; and as these subjects had been but desultorily alluded to in the other works, they are treated of at some length on this occasion. It opens with the distinction of bodies into sonorous and insonorous, and after tracing the analogy between the acute and grave, and the sharp and blunt (of touch), it passes by a rapid transition to the voice, which is dwelt upon at some length. The term ἐνέργεια, which had been used in place of ἐντελεχεία, to express the active as opposed to the potential or negative state of the diaphaneity, is again employed here to signify the analogous and contrasting quality of sound. The distinction between the terms is not very apparent now, although this may not have been the case then; for the ἐνέργεια may have conveyed the idea of action in the transition from potentiality, and so have been more expressive of actual, as opposed to virtual light or sound. Thus, if sound be a quality or condition, it may be active, and it may be only virtual or faint; but although to us inaudible, it is not to be supposed that silence any more than darkness is ever absolute; so that the text has limited the range of sound too absolutely by the activity of the sense. Aristotle assigned, as has been said, a high privilege to this sense, because through it instruction is orally conveyed, and thus the blind from birth are more intelligent (φρονιμώτεροι), he observes, than "the deaf and dumb;" but the argument would have been more correct had the second term been omitted, as individuals are of necessity dumb when hearing is quite shut out. The phraseology, however, is still sanctioned in common parlance.