[1] Cf. Book II. chap. xix. sec. 1. ‘The perception, which actually accompanies and is annexed to any impression on the body, made by an external object, being distinct from all other modifications of thinking, furnishes the mind with a distinct idea which we call sensation; which is, as it were, the actual entrance of any idea into the understanding by the senses.’
(b) In regard to ideas of reflection.
13. By insisting on Locke’s account of the relation between the ideas of sensation and those of reflection we might be brought to a different but not more luminous conclusion. In the passages quoted above, where this relation is most fully spoken of, it appears that the latter are essentially sequent to those of sensation. ‘In time the mind comes to reflect on its own operations, about the ideas got by sensation, and thereby stores itself with a new set of ideas, which I call ideas of reflection.’ Of these only two are primary and original (Book II. c. xxi. sec. 73), viz. motivity or power of moving, with which we are not at present concerned, and perceptivity or power of perception. But according to Locke, as we have seen, there cannot be any, the simplest, idea of sensation without perception. If, then, the idea of perception is only given later and upon reflection, we must suppose perception to take place without any idea of it. But with Locke to have an idea and to perceive are equivalent terms. We must thus conclude that the beginning of knowledge is an unperceived perception, which is against his express statement elsewhere (Book II. c. xxvii. sec. 9), that it is ‘impossible for any one to perceive without perceiving that he does perceive.’
What is the ‘tablet’ impressed?
14. Meanwhile a perpetual equivocation is kept up between a supposed impression on the ‘outward parts,’ and a supposed impression on the ‘tablet of the mind.’ It is not the impression upon, or a motion in, the outward parts, as Locke admits, that constitutes the idea of sensation. It is not an agitation in the tympanum of the ear, or a picture on the retina of the eye, that we are conscious of when we see a sight or hear a sound. [1] The motion or impression, however, has only, as he seems to suppose, to be ‘continued to the brain,’ and it becomes an idea of sensation. Notwithstanding the rough line of distinction between soul and body, which he draws elsewhere, his theory was practically governed by the supposition of a cerebral something, in which, as in a third equivocal tablet, the imaginary mental and bodily tablets are blended. If, however, the idea of sensation, as an object of the understanding when a man thinks, differs absolutely from ‘a motion of the outward parts,’ it does so no less absolutely, however language and metaphor may disguise the difference, from such motion as ‘continued to the brain.’ An instructed man, doubtless, may come to think about a motion in his brain, as about a motion of the earth round the sun, but to speak of such motion as an idea of sensation or an immediate object of intelligent sense, is to confuse between the object of consciousness and a possible physical theory of the conditions of that consciousness. It is only, however, by such an equivocation that any idea, according to Locke’s account of the idea, can be described as an ‘impression’ at all, or that the representation of the mind as a tablet, whether born blank or with characters stamped on it, has even an apparent meaning. A metaphor, interpreted as a fact, becomes the basis of his philosophical system.
[1] Cf. Locke’s own statement (Book III. c. iv. sec. 10). ‘The cause of any sensation, and the sensation itself, in all the simple ideas of one sense, are two ideas; and two ideas so different and distant one from another, that no two can be more so.’
Does the mind make impressions on itself?
15. As applied to the ideas of reflection, indeed, the metaphor loses even its plausibility. In its application to the ideas of sensation it gains popular acceptance from the ready confusion of thought and matter in the imaginary cerebral tablet, and the supposition of actual impact upon this by ‘outward things.’ But in the case of ideas of reflection, it is the mind that at once gives and takes the impression. It must be supposed, that is, to make impressions on itself. There is the further difficulty that as perception is necessary in order to give an idea of sensation, the impress of perception must be taken by the mind in its earliest receptivity; or, in other words, it must impress itself while still a blank, still void of any ‘furniture’ wherewith to make the impression. There is no escape from this result unless we suppose perception to precede the idea of it by some interval of time, which lands us, as we have seen, in the counter difficulty of supposing an unperceived perception. Locke disguises the difficulty from himself and his reader by constantly shifting both the receptive subject and the impressive matter. We find the ‘tablet’ perpetually receding. First it is the ‘outward part’ or bodily organ. Then it is the brain, to which the impression received by the outward part must somehow be continued, in order to produce sensation. Then it is the perceptive mind, which takes an impression of the sensation or has an idea of it. Finally, it is the reflective mind, upon which in turn the perceptive mind makes impressions. But the hasty reader, when he is told that the mind is passively impressed with ideas of reflection, is apt to forget that the matter which thus impresses it is, according to Locke’s showing, simply its perceptive, i.e. its passive, self.
Source of these difficulties. The ‘simple’ idea, as Locke describes it, is a complex idea of substance and relation.
16. The real source of these embarrassments in Locke’s theory, it must be noted, lies in the attempt to make the individual consciousness give an answer to its interrogator as to the beginning of knowledge. The individual looking back on an imaginary earliest experience pronounces himself in that experience to have been simply sensitive and passive. But by this he means consciously sensitive of something and consciously passive in relation to something. That is, he supposes the primitive experience to have involved consciousness of a self on the one hand and of a thing on the other, as well as of a relation between the two. In the ‘idea of sensation’ as Locke conceived it, such a consciousness is clearly implied, notwithstanding his confusion of terms. The idea is a perception, or consciousness of a thing, as opposed to a sensation proper or affection of the bodily organs. Of the perception, again, there is an idea, i.e. a consciousness by the man, in the perception, of himself in negative relation to the thing that is his object, and this consciousness (if we would make Locke consistent in excluding an unperceived perception) must be taken to go along with the perceptive act itself. No less than this indeed can be involved in any act that is to be the beginning of knowledge at all. It is the minimum of possible thought or intelligence, and the thinking man, looking for this beginning in the earliest experience of the individual human animal, must needs find it there. But this means no less than that he is finding there already the conceptions of substance and relation. Hence a double contradiction: firstly, a contradiction between the primariness of self-conscious cognisance of a thing, as the beginning of possible knowledge, on the one hand, and the primariness of animal sensation in the history of the individual man on the other; secondly, a contradiction between the primariness in knowledge of the ideas of substance and relation, and the seemingly gradual attainment of those ‘abstractions’ by the individual intellect. The former of these contradictions is blurred by Locke in the two main confusions which we have so far noticed: (a) the confusion between sensation proper and perception, which is covered under the phrase ‘idea of sensation;’ a phrase which, if sensation means the first act of intelligence, is pleonastic, and if it means the ‘motion of the outward parts continued to the brain,’ is unmeaning; and (b) the confusion between the physical affection of the brain and the act of the self-conscious subject, covered under the equivocal metaphor of impression. The latter contradiction, that concerning the ideas of substance and relation, has to be further considered.