A Treatise of Human Nature · David Hume
GENERAL INTRODUCTION TO VOL. I.
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.
How this contradiction is disguised. 17. It is not difficult to show that to have a simple idea, according to Locke’s account of it, means to have already the conception of substance and relation, which are yet according to him ‘complex and derived ideas,’ ‘the workmanship of the mind’ in opposition to its original material, the result of its action in opposition to what is given it as passive. The equivocation in terms under which this contradiction is generally covered is that between ‘idea’ and ‘quality.’ ‘Whatever the mind perceives in itself, or is the immediate object of perception, thought, or understanding, that I call _idea_; and the power to produce that idea I call quality of the subject wherein that power is. Thus a snowball having power to produce in us the ideas of white, cold, and round, the powers to produce these ideas in us, as they are in the snowball, I call qualities; and as they are sensations or perceptions in our understandings, I call them ideas; which ideas, if I speak of sometimes as in the things themselves, I would be understood to mean those qualities in the object which produce them in us.’ (Book II. chap. viii. sec. 8.) Locke’s way of interchanging ‘idea’ and ‘quality’ and its effects.
18. An equivocation is not the less so because it is announced. It is just because Locke allows himself at his convenience to interchange the terms ‘idea’ and ‘quality’ that his doctrine is at once so plausible and so hollow. The essential question is whether the ‘simple idea,’ as the original of knowledge, is on the one hand a mere feeling, or on the other a thing or quality of a thing. This question is the crux of empirical psychology. Adopting the one alternative, we have to face the difficulty of the genesis of knowledge, as an apprehension of the real, out of mere feeling; adopting the other, we virtually endow the nascent intelligence with the conception of substance. By playing fast and loose with ‘idea’ and ‘quality,’ Locke disguised the dilemma from himself. Here again the metaphor of Impression did him yeoman’s service. The idea, or ‘immediate object of thought,’ being confused with the affection of the sensitive organs, and this again being accounted for as the result of actual impact, it was easy to represent the idea itself as caused by the action of an outward body on the ‘mental tablet.’
Thus Locke speaks of the ‘objects of our senses obtruding their particular ideas on our minds, whether we will or no.’ (Book II. chap. i. sec. 25.) This sentence holds in solution an assumption and two fallacies. The assumption (with which we have no further concern here) is the physical theory that matter affects the sensitive organs in the way of actual impact. Of the fallacies, one is the confusion between this affection and the idea of which it is the occasion to the individual; the other is the implication that this idea, as such, in its prime simplicity, recognises itself as the result of, and refers itself as a quality to, the matter supposed to cause it. This recognition and reference, it is clearly implied, are involved in the idea itself, not merely made by the philosopher theorising it. Otherwise the ‘obtrusion’ would be described as of a property or effect, not of an idea, which means, it must be remembered, the object of consciousness just as the object of consciousness. Of the same purport is the statement that ‘the mind is furnished with simple ideas as they are found in exterior things.’
(Book II. chap, xxiii. sec. 1.) It only requires a moment’s consideration, indeed, to see that the beginning of consciousness cannot be a physical theory, which, however true it may be and however natural it may have become to us, involves not only the complex conception of material impact, but the application of this to a case having no palpable likeness to it. But the ‘interrogator of consciousness’ finds in its primitive state just what he puts there, and thus Locke, with all his pains ‘to set his mind at a distance from itself,’ involuntarily supposes it, in the first element of intelligence, to ‘report’ that action of matter upon itself, which, as the result of a familiar theory--involving not merely the conceptions of substance, power, and relation, but special qualifications of these--it reports to the educated man. Primary and secondary qualities of bodies.
19. This will appear more clearly upon an examination of his doctrine of ‘the ideas of primary and secondary qualities of bodies.’ The distinction between them he states as follows. The primary qualities of bodies are ‘the bulk, figure, number, situation, motion, and rest of their solid parts; these are in them, whether we perceive them or no; and when they are of that size that we can discover them, we have by these an idea of the thing as it is in itself.’ ... Thus ‘the ideas of primary qualities are resemblances of them, and their patterns do really exist in the bodies themselves. But the ideas produced in us by the secondary qualities have no resemblance of them at all. There is nothing like them existing in the bodies themselves. They are in the bodies, we denominate from them, only a power to produce these sensations in us; and what is sweet, blue, or warm in idea is but the certain bulk, figure, and motion of the insensible parts in the bodies themselves which we call so.’ This power is then explained to be of two sorts: _(a)_ ‘The power that is in any body, by reason of its insensible primary qualities, to operate after a peculiar manner on any of our senses, and thereby produce in us the different ideas of several colours, sounds, smells, tastes, &c. These are usually called sensible qualities, _(b)_ The power that is in any body, by reason of the particular constitution of its primary qualities, to make such a change in the bulk, figure, texture, and motion of another body, as to make it operate differently on our senses from what it did before. Thus the sun has a power to make wax white, and fire to make lead fluid. These are usually called powers.’ (Book II. chap. viii. sec. 15, 23.)
‘Simple idea’ represented as involving a theory of its own cause. 20. What we have here is a theory of the causes of simple ideas; but we shall find Locke constantly representing this theory as a simple idea itself, or the simple idea as involving this theory. By this unconscious device he is enabled readily to exhibit the genesis of knowledge out of ‘simple ideas,’ but it is at the cost of converting these into ‘creations of the mind,’ which with him are the antitheses of ‘facts’ or ‘reality.’ The process of conversion takes a different form as applied respectively to the ideas of primary and to those of secondary qualities. We propose to follow it in the latter application first. Phrases in which this is implied.
21. The simple idea caused by a quality he calls the idea _of_ that quality. Under cover of this phrase, he not only identifies the idea of a primary quality with the quality itself of which he supposes it to be a copy, but he also habitually regards the idea of a secondary quality as the consciousness of a quality _of a thing_, though under warning that the quality as it is to consciousness is not as it is in the thing. This reservation rather adds to the confusion. There are in fact, according to Locke, as appears from his distinction between the ‘nominal’ and ‘real essence,’ two different things denoted by every common noun; the thing as it is in itself or in nature, and the thing as it is for consciousness. The former is the thing as constituted by a certain configuration of particles, which is only an object for the physical philosopher, and never fully cognisable even by him; [1] the latter is the thing as we see and hear and smell it. Now to a thing in this latter sense, according to Locke, such a simple idea as to the philosopher is one of a secondary quality (_i.e._ not a copy, but an effect, of something in a body), is already in the origin of knowledge referred as a quality, though without distinction of primary and secondary. He does not indeed state this in so many words. To have done so might have forced him to reconsider his doctrine of the mere passivity of the mind in respect of simple ideas. But it is implied in his constant use of such phrases as ‘reports of the senses,’ ‘inlet through the senses’--which have no meaning unless something is reported, something let in--and in the familiar comparison of the understanding to a ‘closet, wholly shut from light, with only some little opening left, to let in external visible resemblances, or ideas, of things without.’ (Book II. chap. xi. sec. 17.)
It is true that, in concert with that ‘thinking gentleman,’ Mr. Molyneux, he had satisfied himself that what we reckon simple ideas are often really inferences from such ideas which by habit have become instinctive; but his account of this habitual process presupposes the reference of sensation to a thing. ‘When we set before our eyes a round globe of any uniform colour, it is certain that the idea thereby imprinted in our mind is of a flat circle, variously shadowed with several degrees of light and brightness coming to our eyes. But we having by use been accustomed to perceive what kind of appearance convex bodies are wont to make in us, what alterations are made in the reflections of light by the difference of the sensible figures of bodies; the judgment presently, by an habitual custom, alters the appearances into their causes. So that from that which truly is variety of colour or shadow, collecting the figure, it makes it pass for a mark of figure, and frames to itself the perception of a convex figure, and an uniform colour.’
(Book II. chap. ix. sec. 8.) The theory here stated involves two assumptions, each inconsistent with the simplicity of the simple idea. _(a)_ The actual impression of the ‘plane variously coloured’ is supposed to pronounce itself to be of something outward. Once call the sensation an ‘impression,’ indeed, or call it anything, and this or an analogous substantiation of it is implied. It is only as thus reporting something ‘objective’ that the simple idea of the plane variously coloured gives anything to be corrected by the ‘perception of the kind of appearance convex bodies are wont to make in us,’ _i.e._ ‘of the alterations made in the reflections of light by the difference of the sensible figure of bodies.’ This perception, indeed, as described, is already itself just the instinctive judgment which has to be accounted for, and though this objection might be met by a better statement, yet no statement could serve Locke’s purpose which did not make assumption _(b)_ that sensations of light and colour--‘simple ideas of secondary qualities’--are in the very beginning of knowledge _appearances_, if not of _convex_ bodies, yet of bodies; if not of bodies, yet of something which they reveal, which remains there while they pass away. The simple idea as ‘ectype’ other than mere sensation.
23. The same assumption is patent in Locke’s account of the distinction between ‘real and fantastic,’ ‘adequate and inadequate,’ ideas. This distinction rests upon that between the thing as archetype, and the idea as the corresponding ectype. Simple ideas he holds to be necessarily ‘real’ and ‘adequate,’ because necessarily answering to their archetypes. ‘Not that they are all of them images or representations of what does exist: ... whiteness and coldness are no more in snow than pain is: ... yet are they real ideas in us, whereby we distinguish the qualities that are really in things themselves. For these several appearances being designed to be the marks whereby we are to know and distinguish things which we have to do with, our ideas do as well serve us to that purpose, and are as real distinguishing characters, whether they be only constant effects, or else exact resemblances of something in the things themselves.’ (Book II. chap. xxx. sec. 2.) The simple idea, then, is a ‘mark’ or ‘distinguishing character,’ either as a copy or as an effect, of something other than itself. Only as thus regarded, does the distinction between real and fantastic possibly apply to it. So too with the distinction between true and false ideas.
As Locke himself points out, the simple idea in itself is neither true nor false. It can become so only as ‘referred to something extraneous to it.’ (Book II. chap, xxxii. sec. 4.) For all that, he speaks of simple ideas as true and necessarily true, because ‘being barely such perceptions as God has fitted us to receive, and given power to external objects to produce in us by established laws and ways ... their truth consists in nothing else but in such appearances as are produced in us, and must be suitable to those powers He has placed in external objects, or else they could not be produced in us.’ (Book II. chap, xxxii. sec. 14.) Here again we are brought to the same point. The idea is an ‘appearance’ of something, necessarily true when it cannot seem to be the appearance of anything else than that of which it is the appearance. We thus come to the following dilemma. Either the simple idea is referred to a thing, as its pattern or its cause, or it cannot be regarded as either real or true. If it is still objected that it need not be so referred in the beginning of knowledge, though it comes to be so in the developed intelligence, the answer is the further question, how can that be knowledge even in its most elementary phase--the phase of the reception of simple ideas --which is not a capacity of distinction between real and apparent, between true and false? If its beginning is a mode of consciousness, such as mere sensation would be--which, because excluding all reference, excludes that reference of itself to something else without which there could be no consciousness of a distinction between an ‘is’ and an ‘is not,’ and therefore no true judgment at all--how can any repetition of such modes give such a judgment? [1]
As we have seen, the whole theory of this (the second) book turns upon the supposition that the simple idea of sensation is in every case an idea of a sensible quality, and that it is so, not merely for us, considering it _ex parte post_, but consciously for the individual subject, which can mean nothing else than that it distinguishes itself from, and refers itself to, a thing. Locke himself, indeed, according to his plan of bringing in a ‘faculty of the mind’ whenever it is convenient, would perhaps rather have said that it is so distinguished and referred ‘by the mind.’ He considers the simple idea not, as it truly is, the mind itself in a certain relation, but a datum or material of the mind, upon which it performs certain operations as upon something other than itself, though all the while it is constituted, at least in its actuality, by this material. Between the reference of the simple idea to the thing, however, by itself and ‘by the mind,’ there is no essential difference. In either case the reference is inconsistent with the simplicity of the simple idea; and if the latter expression avoids the seeming awkwardness of ascribing activity to the idea, it yet ascribes it to the mind in that elementary stage in which, according to Locke, it is merely receptive.
And is equivalent to what he afterwards calls ‘knowledge of identity’. Only as such can it be named. 25. So much for the theory ‘of ideas.’ As if, however, in treating of ideas he had been treating of anything else than knowledge, he afterwards considers ‘knowledge’ in a book by itself (the fourth) under that title, and here the question as to the relation between idea and thing comes before him in a somewhat different shape. According to his well-known definition, knowledge is the perception of the agreement or disagreement of any of our ideas. The agreement or disagreement may be of four sorts. It may be in the way (1) of identity, (2) of relation, (3) of co-existence, (4) of real existence. In his account of the last sort of agreement, it may be remarked by the way, he departs at once and openly from his definition, making it an agreement, not of idea with idea, but of an idea with ‘actual real existence.’ The fatal but connatural wound in his system, which this inconsistency marks, will appear more fully below. For the present, our concern is for the adjustment of the definition of knowledge to the doctrine of the simple idea as the beginning of knowledge. According to the definition, it cannot be the simple idea, as such, that constitutes this beginning, but only the perception of agreement or disagreement between simple ideas.
‘There could be no room,’ says Locke distinctly, ‘for any positive knowledge at all, if we could not distinguish any relation between our ideas.’ (Book IV. chap. i. sec. 5.) Yet in the very context where he makes this statement, the perception of relation is put as a distinct kind of knowledge apart from others. In his account of the other kinds, however, he is faithful to his definition, and treats each as a perception (_i.e._ a judgment) of a relation in the way of agreement or disagreement. The primary knowledge is that of identity--the knowledge of an idea as identical with itself. ‘A man infallibly knows, as soon as ever he has them in his mind, that the ideas he calls _white_ and _round_, are the very ideas they are, and not other ideas which he calls _red_ and _square_.’ (Book IV. chap. i. sec. 4.) Now, as Hume afterwards pointed out, identity is not simple unity. It cannot be predicated of the ‘idea’ as merely single, but only as a manifold in singleness. To speak of an idea as the ‘same with itself’ is unmeaning unless it mean ‘same with itself _in its manifold appearances_’ _i.e._ unless the idea is distinguished, as an object existing continuously, from its present appearance.
Thus ‘the infallible knowledge,’ which Locke describes in the above passage, consists in this, that on the occurrence of a certain ‘idea’ the man _recognises_ it as one, which at other times of its occurrence he has called ‘_white_.’ Such a ‘synthesis of recognition,’ however, expressed by the application of a common term, implies the reference of a present sensation to a permanent object of thought, in this case the object thought under the term ‘white,’ so that the sensation becomes an idea of that object. Were there no such objects, there would be no significant names, but only noises; and were the present sensation not so referred, it would not be named. It may be said indeed that the ‘permanent object of thought’ is merely the instinctive result of a series of past resembling sensations, and that the common name is merely the register of this result. But the question is thus merely thrown further back. Unless the single fleeting sensation was, to begin with, fixed and defined by relation to and distinction from something permanent--in other words, unless it ceased to be a mere sensation--how did it happen that other sensations were referred to it, as different cases of an identical phenomenon, to which the noise suggested by it might be applied as a sign? The same implied in calling it an idea of an object.
26. This primary distinction and relation of the simple idea Locke implicitly acknowledges when he substitutes for the simple idea, as in the passage last quoted, the man’s knowledge that he has the idea; for such knowledge implies the distinction of the idea from its permanent conscious subject, and its determination by that negative relation. [1] Thus determined, it becomes itself a permanent object, or (which comes to the same) an idea _of an object_; a phrase which Locke at his convenience substitutes for the mere idea, whenever it is wanted for making his theory of knowledge square with knowledge itself. Once become such an object, it is a basis to which other sensations, like and unlike, may be referred as differentiating attributes. Its identity becomes a definite identity. [1] Cf. the passage in Book II. chap. vii. sec. 7. ‘When ideas are in our minds, we consider them as being actually there.’ The mere ‘idea’ is in fact essentially different from the ‘consideration of it as actually there,’ as sensation is different from thought. The ‘consideration, &c.,’ really means the thought of the ‘idea’ (sensation) as determined by relation to the conscious subject. Made _for_, not _by_, us, and therefore according to Locke really existent.
27. Upon analysis, then, of Locke’s account of the most elementary knowledge, the perception of identity or agreement of an idea with itself, we find that like the ‘simple idea,’ which he elsewhere makes the beginning of knowledge, it really means the reference of a sensation to a conception of a permanent object or subject, [1] either in such a judgment as ‘this is white’ (_sc._ a white thing), or in the more elementary one, ‘this is an object to me.’ In the latter form the judgment represents what Locke puts as the consciousness, ‘I have an idea,’ or as the ‘consideration that the idea is actually there;’ in the former it represents what he calls ‘the knowledge that the idea which I have in my mind and which I call white is the very idea it is, and not the idea which I call red.’ It is only because _referred_, as above, that the sensation is in Locke’s phraseology ‘a testimony’ or ‘report’ of something. As we said above, his notion of the beginning of knowledge is expressed not merely in the formula ‘I have an idea different from other ideas,’ but with the addition, ‘which I did not make for myself.’ [2] The simple idea is supposed to testify to something without that caused it, and it is this interpretation of it which makes it with him the ultimate criterion of reality. But unless it were at once distinguished from and referred to both a thing of which it is an effect and a subject of which it is an experience, it could not in the first place testify to anything, nor secondly to a thing as made for, not by, the subject. This brings us, however, upon Locke’s whole theory of ‘real existence,’ which requires fuller consideration.
Text from Project Gutenberg, public domain in the United States.