87. We have already seen how Locke, in his doctrine of secondary qualities of substances, practically gets over this difficulty; how he first projects out of the simple ideas, under relations which it requires a mind to constitute, a cognisable system of things, and then gives content and definiteness to the simple ideas in us by treating them as manifestations of this system of things. In the doctrine of propositions, the proper correlative to the reduction of the real to the present simple idea, as that of which we cannot get rid, would be the reduction of the ‘real proposition’ to the mere ‘it is now felt.’ If the matter-of-fact is to be that in consciousness which is independent of the ‘work of the mind’ in comparing and compounding, this is the only possible expression for it. It states the only possible ‘real essence,’ which yet is an essence of nothing, for any reference of it to a thing, if the thing is outside consciousness, is an impossibility; and if it is within consciousness, implies an ‘invention of the mind’ both in the creation of a thing, ‘always the same with itself,’ out of perishing feelings, and in the reference of the feelings to such a thing. Thus carried out, the antithesis between ‘fact’ and ‘creation of the mind’ becomes self-destructive, for, one feeling being as real as another, it leaves no room for that distinction between the real and fantastic, to the uncritical sense of which it owes its birth. To avoid this fusion of dream-land and the waking world, Locke avails himself of the distinction between the idea (i.e. feeling) as in the mind, which is not convertible with reality, and the idea as somewhere else, no one can say where—‘the actual sensation’—which is so convertible. The distinction, however, must either consist in degrees of liveliness, in which case there must be a corresponding infinity of degrees of reality or unreality, or else must presuppose a real existence from which the feeling, if ‘actual sensation,’ is—if merely ‘in the mind’ is not—derived. Such a real existence either is an object of consciousness, or is not. If it is not, no distinction between one kind of feeling and another can for consciousness be derived from it. If it is, then, granted the distinction between given feelings and creations of the mind, it must fall to the latter, and a ‘thing of the mind’ turns out to be the ground upon which ‘fact’ is opposed to ‘things of the mind.’
Two meanings of real essence.
88. It remains to exhibit briefly the disguises under which these inherent difficulties of his theory of essence appear in Locke. Throughout, instead of treating ‘essence’ altogether as a fiction of the mind—as it must be if feelings in simplicity and singleness are alone the real—he treats indeed as a merely ‘nominal essence’ every possible combination of ideas of which we can speak, but still supposes another essence which is ‘real.’ But a real essence of what? Clearly, according to his statements, of the same ‘thing’ of which the combination of ideas in the mind is the nominal essence. Indeed, there is no meaning in the antithesis unless the ‘something,’ of which the latter essence is so nominally, is that of which it is not so really. So says Locke, ‘the nominal essence of gold is that complex idea the word gold stands for; let it be, for instance, a body yellow, of a certain weight, malleable, fusible, and fixed. But the real essence is the constitution of the insensible parts of that body, on which those qualities and all the other properties of gold depend.’ (Book III. chap. vi. sec. 2.) Here the notion clearly is that of one and the same thing, of which we can only say that it is a ‘body,’ a certain complex of ideas—yellowness, fusibility, &c.—is the nominal, a certain constitution of insensible parts the real, essence. It is on the real essence, moreover, that the ideas which constitute the nominal depend. Yet while they are known, the real essence (as appears from the context) is wholly unknown. In this case, it would seem, the cause is not known from its effects.
According to one, it is a collection of ideas as qualities of a thing:
89. There are lurking here two opposite views of the relation between the nominal essence and the real thing. According to one view, which prevails in the later chapters of the Second Book and in certain passages of the third, the relation between them is that with which we have already become familiar in the doctrine of substance—that, namely, between ideas as in us and the same as in the thing. (Book II, chap. xxiii. secs. 9 and 10.) No distinction is made between the ‘idea in the mind’ and the ‘actual sensation.’ The ideas in the mind are also in the thing, and thus are called its qualities, though for the most part they are so only secondarily, i.e. as effects of other qualities, which, as copied directly in our ideas, are called primary, and relatively to these effects are called powers. These powers have yet innumerable effects to produce in us which they have not yet produced. (Book II. chap. xxxi. sec. 10.) Those which have been so far produced, being gathered up in a complex idea to which a name is annexed, form the ‘nominal essence’ of the thing. Some of them are of primary qualities, more are of secondary. The originals of the former, the powers to produce the latter, together with powers to produce an indefinite multitude more, will constitute the ‘real essence,’ which is thus ‘a standard made by nature,’ to which the nominal essence is opposed merely as the inadequate to the adequate. The ideas, that is to say, which are indicated by the name of a thing, have been really ‘found in it’ or ‘produced by it,’ but are only a part of those that remain to be found in it or produced by it. It is in this sense that Locke opposes the adequacy between nominal and real essence in the case of mixed modes to their perpetual inadequacy in the case of ideas of substances. The combination in the one case is artificially made, in the other is found and being perpetually enlarged. This he illustrates by imagining the processes which led Adam severally to the idea of the mixed mode ‘jealousy’ and that of the substance ‘gold.’ In the former process Adam ‘put ideas together only by his own imagination, not taken from the existence of anything … the standard there was of his own making.’ In the latter, ‘he has a standard made by nature; and therefore being to represent that to himself by the idea he has of it, even when it is absent, he puts no simple idea into his complex one, but what he has the perception of from the thing itself. He takes care that his idea be conformable to this archetype.’ (Book III. chap. vi. secs. 46, 47.) ‘It is plain,’ however, ‘that the idea made after this fashion by this archetype will be always inadequate.’
… about real essence in this sense there may be general knowledge.
90. The nominal essence of a thing, then, according to this view, being no other than the ‘complex idea of a substance,’ is a copy of reality, just as the simple idea is. It is a picture or representation in the mind of a thing that does exist by ideas of those qualities that are discoverable in it.’ (Book II. chap. xxxi. secs. 6, 8.) It only differs from the simple idea (which is itself, as abstract, a nominal essence) [1] in respect of reality, because the latter is a copy or effect produced singly and involuntarily, whereas we may put ideas together, as if in a thing, which have never been so presented together, and, on the other hand, never can put together all that exist together. (Book II. chap. xxx. sec. 5, and xxxi. 10.) So far as Locke maintains this view, the difficulty about general propositions concerning real existence need not arise. A statement which affirmed of gold one of the qualities included in the complex idea of that substance, would not express merely an analysis of an idea in the mind, but would represent a relation of qualities in the existing thing from which the idea ‘has been taken.’ These qualities, as in the thing, doubtless would not be, as in us, feelings (or, as Locke should rather have said in more recent phraseology, possibilities of feeling), but powers to produce feeling, nor could any relation between these, as in the thing, be affirmed but such as had produced its copy or effect in actual experience. No coexistence of qualities could be truly affirmed, which had not been found; but, once found—being a coexistence of qualities and not simply a momentary coincidence of feelings—it could be affirmed as permanent in a general proposition. That a relation can be stated universally between ideas collected in the mind, no one denies, and if such collection ‘is taken from a combination of simple ideas existing together constantly in things’ (Book II. chap, xxxii. sec. 18), the statement will hold equally of such existence. Thus Locke contrasts mixed modes, which, for the most part, ‘being actions which perish in the birth, are not capable of a lasting duration,’ with ‘substances, which are the actors; and wherein the simple ideas that make up the complex ideas designed by the name have a lasting union.’ (Book III. chap. vi. sec. 42.)
[1] Book II. chap. xxxi. sec. 12.
But such real essence a creature of thought.
91. In such a doctrine Locke, starting whence he did, could not remain at rest. We need not here repeat what has been said of it above in the consideration of his doctrine of substance. Taken strictly, it implies that ‘real existence’ consists in a permanent relation of ideas, said to be of secondary qualities, to each other in dependence on other ideas, said to be of primary qualities. In other words, in order to constitute reality, it takes ideas out of that particularity in time and place, which is yet pronounced the condition of reality, to give them an ‘abstract generality’ which is fictitious, and then treats them as constituents of a system of which the ‘invented’ relations of cause and effect and of identity are the framework. In short, it brings reality wholly within the region of thought, distinguishing it from the system of complex ideas or nominal essences which constitute our knowledge, not as the unknown opposite of all possible thought, but only as the complete from the incomplete. To one who logically carried out this view, the ground of distinction between fact and fancy would have to be found in the relation between thought as ‘objective,’ or in the world, and thought as so far communicated to us. Here, however, it could scarcely be found by Locke, with whom ‘thought’ meant simply a faculty of the ‘thinking thing,’ called a ‘soul,’ which might ride in a coach with him from Oxford to London. (Book II. chap, xxiii. sec. 20.) Was the distinction then to disappear altogether?