Only the knowledge that something is, not what it is.
105. All that is gained, then, by the conversion of the feeling of touch, pure and simple, into the idea of a body touched, is the supposition that there is a real existence which does not come and go with the sensations. As to what this existence is, as to its real essence, we can have no knowledge but such as is given in a present sensation. [1] Any essence of it, otherwise known, could only be a nominal essence, a relation of ideas in our minds: it would lack the condition in virtue of which alone a datum of consciousness can claim to be representative of reality, that of being an impression made by a body now operating upon us. (Book III. chap. v. sec. 2, and Book IV. chap. xi. sec. 1.) The memory of such impression, however faithful, will still only report a past reality. It will itself be merely ‘an idea in the mind.’ Neither it nor its relation to any present sensation result from the immediate impact of body, and in consequence neither ‘really exists.’ All that can be known, then, of the real, in other words, the whole real essence of body, as it is for us, reduces itself to that which can at any moment be ‘revealed’ in a single sensation apart from all relation to past sensations; and this, as we have seen, is nothing at all.
[1] Cf. Book III. chap. vi. sec. 6: ‘As to the real essences of substances, we only suppose their being, without precisely knowing what they are.’ The appearance of the qualification ‘precisely,’ as we shall see below, marks an oscillation from the view, according to which ‘real essence’ is the negation of the knowable to the view according to which our knowledge of it is merely inadequate.
How it is that the real essence of things, according to Locke, perishes with them, yet is immutable.
106. Thus that reduction of reality to that of which nothing can be said, which follows from its identification with particularity in time, follows equally from its identification with the resistance of body, or (which comes to the same) from the notion of an ‘outer sense’ being its organ; since it is only that which now resists, not a general possibility of resistance nor a relation between the resistances of different times, that can be regarded as outside the mind. In Locke’s language, it is only a particular parcel of matter that can be so regarded. Of such a parcel, as he rightly says, it is absurd to ask what is its essence, for it can have none at all. (See above, paragraph 94.) As real, it has no quality save that of being a body or of being now touched—a quality, which as all things real have it and have none other, cannot be a differentia of it. When we consider that this quality may be regarded equally as immutable and as changing from moment to moment, we shall see the ground of Locke’s contradiction of himself in speaking of the real thing sometimes as indestructible, sometimes as in continual dissolution. ‘The real constitutions of things begin and perish with them.’ (Book III. chap. iii. sec. 19.) That is, the thing at one moment makes an impact on the sensitive tablet—in the fact that it does so lie at once its existence and its essence—but the next moment the impact is over, and with it thing and essence, as real, have disappeared. Another impact, and thus another thing, has taken its place. But of this the real essence is just the same as that of the previous thing, namely, that it may be touched, or is solid, or a body, or a parcel of matter; nor can this essence be really lost, since than it there is no other reality, all difference of essence, as Locke expressly says, [1] being constituted by abstract ideas and the work of the mind. It follows that real change is impossible. A parcel of matter at one time is a parcel of matter at all times. Thus we have only to forget that the relation of continuity between the parcels, not being an idea caused by impact, should properly fall to the unreal—though only on the same principle as should that of distinctness between the times—and we find the real in a continuity of matter, unchangeable because it has no qualities to change. It may seem strange that when this notion of the formless continuity of the real being gets the better of Locke, a man should be the real being which he takes as his instance. ‘Nothing I have is essential to me. An accident or disease may very much alter my colour or shape; a fever or fall may take away my reason or memory, or both; and an apoplexy leave neither sense nor understanding, no, nor life.’ (Book III. chap. vi. sec. 4.) But as the sequel shows, the man or the ‘I’ is here considered simply as ‘a particular corporeal being,’ i.e. as the ‘parcel of matter’ which alone (according to the doctrine of reality now in view) can be the real in man, and upon which all qualities are ‘superinductions of the mind.’ [2]
[1] Book III. chap. vi. sec. 4: ‘Take but away the abstract ideas by which we sort individuals, and then the thought of anything essential to any of them instantly vanishes.’
[2] See a few lines below the passage quoted: ‘So that if it be asked, whether it be essential to me, or any other particular corporeal being, to have reason? I say, no; no more than it is essential to this white thing I write on to have words in it.’
Only about qualities of matter, as distinct from matter itself, that
Locke feels any difficulty.
107. We may now discern the precise point where the qualm as to clothing reality with such superinductions commonly returns upon Locke. The conversion of feeling into body felt and of the particular time of the feeling into an individuality of the body, and, further, the fusion of the individual bodies, manifold as the times of sensation, into one continued body, he passes without scruple. So long as these are all the traces of mental fiction which ‘matter,’ or ‘body,’ or ‘nature’ bears upon it, he regards it undoubtingly as the pure ‘privation’ of whatever belongs to the mind. But so soon as cognisable qualities, forming an essence, come to be ascribed to body, the reflection arises that these qualities are on our side ideas, and that so far as they are permanent or continuous they are not ideas of the sort which can alone represent body as the ‘real’ opposite of mind; they are not the result of momentary impact; they are not ‘actually present sensations.’ Suppose them, however, to have no permanence—suppose their reality to be confined to the fleeting ‘now’—and they are no qualities, no essence, at all. There is then for us no real essence of body or nature; what we call so is a creation of the mind.
These, as knowable, must be our ideas, and therefore not a ‘real essence’.