A Treatise of Human Nature · David Hume
GENERAL INTRODUCTION TO VOL. I.
When he afterwards, in virtual contradiction to this limitation, finds the reality of moral and mathematical ideas just in that sole relation to the mind, as its products, which he had previously made the source of all unreality, he forces upon us the explanation which he does not himself give, that unreality does not lie in either relation as opposed to the other, but in the confusion of any relation with another. It is for lack of this explanation that Locke himself, as we have seen, finds in the liveliness and involuntariness of ideas the sole and sufficient tests (not _constituents_) of their reality; though they are obviously tests which put the dreams of a man in a fever upon the same footing with the ‘impressions’ of a man awake, and would often prove that unreal after dinner which had been proved real before. There is a well-known story of a man who in a certain state of health commonly saw a particular gory apparition, but who, knowing its origin, used to have himself bled till it disappeared.
The reality of the apparition lay, he knew, in some relation between the circulation of his blood and his organs of sight, in distinction from the reality existing in the normal relations of his visual organs to the light: and in his idea, accordingly, there was nothing unreal, because he did not confuse the one relation with the other. Locke’s doctrine, however, would allow of no distinction between the apparition as it was for such a man and as it would be for one who interpreted it as an actual ‘ghost.’ However interpreted, the liveliness and the involuntariness of the idea remain the same, as does its relation to an efficient cause. If in order to its reality the cause must be an ‘outward body,’ then it is no more real when rightly, than when wrongly, interpreted; while on the ground of liveliness and involuntariness it is as real when taken for a ghost as when referred to an excess of blood in the head. Berkeley retains this notion, only substituting ‘God’ for ‘body’.
189. As has been pointed out above, it is in respect not of the ‘ratio cognoscendi’ but of the ‘ratio essendi’ that Berkeley’s doctrine of reality differs from Locke’s. With him it is not as an effect of an outward body, but as an immediate effect of God, that an ‘idea of sense’ is real. Just as with Locke real ideas and matter serve each to explain the other, so with Berkeley do real ideas and God. If he is asked, What is God? the answer is, He is the efficient cause of real ideas; if he is asked, What are real ideas? the answer is, Those which God produces, as opposed to those which we make for ourselves. To the inevitable objection, that this is a logical see-saw, no effective answer can be extracted from Berkeley but this--that we have subjective tests of the reality of ideas apart from a knowledge of their cause. In his account of these Berkeley only differs from Locke in adding to the qualifications of liveliness and involuntariness those of ‘steadiness, order, and coherence’ in the ideas. This addition may mean either a great deal or very little.
To us it may mean that the distinction of real and unreal is one that applies not to feelings but to the conceived relations of feelings; not to events as such, but to the intellectual interpretation of them. The occurrence of a feeling taken by itself (it may be truly said) is neither coherent nor incoherent; nor can the sequence of feelings one upon another with any significance be called coherence, since in that case an incoherence would be as impossible as any failure in the sequence. As little can we mean by such coherence an usual, by incoherence an unusual, sequence of feelings. If we did, every sequence not before experienced--such, for instance, as is exhibited by a new scientific experiment--being unusual, would have to be pronounced incoherent, and therefore unreal. Coherence, in short, we may conclude, is only predicable of a system of relations, not felt but conceived; while incoherence arises from the attempt of an imperfect intelligence to think an object under relations which cannot ultimately be held together in thought. The qualification then of ‘ideas’ as coherent has in truth no meaning unless ‘idea’ be taken to mean not _feeling_ but _conception_: and thus understood, the doctrine that coherent ideas _are_ (Berkeley happily excludes the notion that they merely _represent_) the real, amounts to a clear identification of the real with the world of conception.
Not regarding the world as a system of intelligible relations, he could not regard God as the subject of it. 190. If such idealism were Berkeley’s, his inference from the ‘ideality’ of the real to spirit and God would be more valid than it is. To have got rid of the notion that the world first exists and then is thought of--to have seen that it only really exists as thought of--is to have taken the first step in the only possible ‘proof of the being of God,’ as the self-conscious subject in relation to which alone an intelligible world can exist, and the presence of which in us is the condition of our knowing it. [1] But there is nothing to show that in adopting coherence as one test, among others, of the reality of ideas, he attached to it any of the significance exhibited above. He adopted it from ordinary language without considering how it affected his view of the world as a succession of feelings. That still remained to him a sufficient account of the world, even when he treated it as affording intuitive certainty of a soul ‘naturally immortal,’ and demonstrative certainty of God. He is not aware, while he takes his doctrine of such certainty from Locke, that he has left out, and not replaced, the only solid ground for it which Locke’s system suggested.
Such logical necessity indeed is misinterpreted when made a ground for believing the real existence either of a multitude of independent things, for everything is a ‘retainer’ to everything else; [1] or of a separation of the thinking from the material substance, since, according to Locke’s own showing, they at least everywhere overlap; [2] or of an absolutely last substance, which because last would be unknowable: but it is evidence of the action of a synthetic principle of self-consciousness without which all reference of feelings to mutually-qualified subjects and objects, and therefore all knowledge, would be impossible. It is idle, however, with Berkeley so to ignore the action of this principle on the one side as to pronounce the material world a mere succession of feelings, and so to take it for granted on the other as to assert that every feeling implies relation to a conscious substance.
Upon such a method the latter assertion has nothing to rest on but an appeal to the individual’s consciousness--an appeal which avails as much or as little for material as for thinking substance, and, in face of the apparent fact that with a knock on the head the conscious independent substance may disappear altogether, cannot hold its own against the suggestion that the one substance no less than the other is reducible to a series of feelings, so closely and constantly sequent on each other as to seem to coalesce. We cannot substitute for this illusory appeal the valid method of an analysis of knowledge, without finding that substantiation in matter is just as necessary to knowledge as substantiation in mind. If this method had been Berkeley’s he would have found a better plan for dealing with the ‘materialism’ in vogue. Instead of trying to show that material substance was a fiction, he would have shown that it was really a basis of intelligible relations, and that thus all that was fictitious about it was its supposed sensibility and consequent opposition to the work of thought. Then his doctrine of matter would itself have established the necessity of spirit, not indeed as substance but as the source of all substantiation. As it was, misunderstanding the true nature of the antithesis between matter and mind, in his zeal against matter he took away the ground from under the spiritualism which he sought to maintain. He simply invited a successor in speculation, of colder blood than himself, to try the solution of spirit in the same crucible with matter.
The reference to this feeling substance, if necessary for any idea, is necessary for all--for the ‘fantastic’ as well as for those of sense--and can therefore afford no ground for distinction between the real and unreal. Instead, however, of being thus led to a truer view of this distinction, as in truth a distinction between the complete and incomplete conception of an intelligible world, he simply puts the feeling substance, when he regards it as God, under an arbitrary limitation, making it relative only to those ideas of which with Locke ‘matter’ was the substance, as opposed to those which Locke had referred to the thinking thing. The direct consequence of this limitation, indeed, might seem to be merely to make God an animal of partial, instead of universal, susceptibility; but this consequence Berkeley avoids by dropping the ordinary notion of substance altogether, so as to represent the ideas of sense not as subsisting in God but as effects of His power--as related to Him, in short, just as with Locke ideas of sense are related to the primary qualities of matter. ‘There must be an active power to produce our ideas, which is not to be found in ideas themselves, for we are conscious that they are inert, nor in matter, since that is but a name for a bundle of ideas; which must therefore be in spirit, since of that we are conscious as active; yet not in the spirit of which we are conscious, since then there would be no difference between real and imaginary ideas; therefore in a Divine Spirit, to whom, however, may forthwith be ascribed the attributes of the spirit of which we are conscious.’ Such is the sum of Berkeley’s natural theology.
The value of Locke’s proof, as an argument from their being something now to their having been something from eternity, lay, we saw, in its convertibility into an argument from the world as a system of relations to a present and eternal subject of those relations. For its being so convertible there was this to be said, that Locke, with whatever inconsistency, at least recognised the constitution of reality by permanent relations, though he treated the mere relation of external efficiency--that in virtue of which we say of nature that it consists of bodies outward to and acting on each other--as if it alone constituted the reality of the world. Berkeley’s reduction of the ‘primary qualities of matter’ to a succession of feelings logically effaces this relation, and puts nothing intelligible, nothing but a name, in its place. The effacement of the distinction between the real and unreal, which would properly ensue, is only prevented by bringing back relation to something under the name of God, either wholly unknown and indeterminate, or else, under a thin disguise, determined by that very relation of external efficiency which, when ascribed to something only nominally different, had been pronounced a gratuitous fiction.
If Berkeley had dealt with the opposition of reality to thought by showing the primary qualities to be conceived relations, and the distinction between the real and unreal to be one between the fully and the defectively conceived, the case would have been different. The real and God would alike have been logically saved. The peculiar embarrassment of Locke’s doctrine we have found to be that it involves the unreality of every object, into the constitution of which there enters any idea of reflection, or any idea retained in the mind, as distinct from the present effect of a body acting upon us--_i.e._ of every object of which anything can be said. With the definite substitution of full intelligibility of relations for present sensibility, as the true account of the real, this embarrassment would have been got rid of. At the same time there would have been implied an intelligent subject of these relations; the ascription to whom, indeed, of moral attributes would have remained a further problem, but who, far from being a ‘Great Unknown,’ would be at least determined by relation to that order of nature which is as necessary to Him as He to it.
But in fact, as we have seen, the notion of the reality of relations, not felt but understood, only appears in Berkeley’s developed philosophy as an after-thought, and the notion of an order of nature, other than our feelings, which enables us to infer what feelings that have never been felt would be, is an unexplained intrusion in it. The same is true of the doctrine, which struggles to the surface in the Third Dialogue, that the ‘sensible world’ is to God not felt at all, but known; that to Him it is precisely not that which according to Berkeley’s refutation of materialism it really is--a series or collection of sensations. These ‘after-thoughts,’ when thoroughly thought out, imply a complete departure from Berkeley’s original interpretation of ‘phenomena’ as simple feelings; but with him, so far from being thought out, they merely suggested themselves incidentally as the conceptions of God and reality were found to require them. In other words, that interpretation of phenomena, which is necessary to any valid ‘collection’ from them of the existence of God, only appears in him as a consequence of that ‘collection’ having been made. To pursue the original interpretation, so that all might know what it left of reality, was the best way of deciding the question of its compatibility with a rational belief in God--a question of too momentous an interest to be fairly considered in itself. Thus to pursue it was the mission of Hume.
Hume’s mission. His account of impressions and ideas. Ideas are fainter impressions. 195. Hume begins with an account of the ‘perceptions of the human mind,’ which corresponds to Locke’s account of ideas with two main qualifications, both tending to complete that dependence of thought on something other than itself which Locke had asserted, but not consistently maintained. He distinguishes ‘perceptions’ (equivalent to Locke’s ideas) into ‘impressions’ and ‘ideas’ accordingly as they are originally produced in feeling or reproduced by memory and imagination, and he does not allow ‘ideas of reflection’ any place in the _original_ ‘furniture of the mind.’ ‘An impression first strikes upon the senses, and makes us perceive heat or cold, thirst or hunger, pleasure or pain, of some kind or other. Of this impression there is a copy taken by the mind, which remains after the impression ceases; and this we call an idea. This idea of pleasure or pain, when it returns upon the soul, produces the new impressions of desire and aversion, hope and fear, which may properly be called impressions of reflection, because derived from it. These, again, are copied by the memory and imagination, and become ideas; which, perhaps, in their turn give rise to other impressions and ideas; so that the impressions are only antecedent to their correspondent ideas, but posterior to those of sensation and derived from them’ (Part I. §2).
He is at the same time careful to explain that the causes from which the impressions of sensation arise are unknown (ibid.), and that by the term ‘impression’ he is not to be ‘understood to express the manner in which our lively perceptions are produced in the soul, but merely the perceptions themselves’. [1] The distinction between impression and idea he treats as equivalent to that between feeling and thinking, which, again, lies merely in the different degrees of ‘force and liveliness’ with which the perceptions, thus designated, severally ‘strike upon the mind.’ [2] Thus the rule which he emphasises [3] ‘that all our simple ideas in their first appearance are derived from simple impressions which are correspondent to them and which they exactly represent,’ strictly taken, means no more than that a feeling must be more lively before it becomes less so. As the reproduced perception, or ‘idea,’ differs in this respect from the original one, so, according to the greater or less degree of secondary liveliness which it possesses, is it called ‘idea of memory,’ or ‘idea of imagination.’ The only other distinction noticed is that, as might be expected, the comparative faintness of the ideas of imagination is accompanied by a possibility of their being reproduced in a different order from that in which the corresponding ideas were originally presented. Memory, on the contrary, ‘is in a manner tied down in this respect, without any power of variation’; [4] which must be understood to mean that, when the ideas are faint enough to allow of variation in the order of reproduction, they are not called ‘ideas of memory.’
To such persons we can but respectfully point out that they have not come in sight of the problem which Locke and his followers, on however false a method, sought to solve; that, however certain may be the correlation between the brain and thought, in the sense that the individual would be incapable of the processes of thought unless he had brain and nerves of a particular sort, yet it is equally certain that every theory of the correlation must presuppose a knowledge of the processes, and leave that knowledge exactly where it was before; that thus their science, valuable like every other science within its own department, takes for granted just what metaphysic, as a theory of knowledge, seeks to explain. When the origin, for instance, of the conception of body or of that of an organic structure is in question, it is in the strictest sense preposterous to be told that body makes the conception of body, and that unless the brain were organic to thought I should not now be thinking. ‘The brain is organic to thought;’ here is a proposition involving conceptions within conceptions--a whole hierarchy of ideas. How am I enabled to re-think these in order, to make my way from the simpler to the more complex, by any iteration or demonstration of the proposition, which no one disputes, or by the most precise examination of the details of the organic structure itself?
Hume’s psychology will not answer it either. 200. ‘Empirical psychology,’ however, claims to have a way of its own for explaining thought, distinct from that of the physiologist, but yet founded on observation, though it is admitted that the observation takes place under difficulties. Its method consists in a history of consciousness, as a series of events or successive states observed in the individual by himself. By tracing such a chain of _de facto_ sequence it undertakes to account for the elements common to all knowledge. Its first concern, then, must be, as we have previously put it, to ascertain what consciousness is to itself at its beginning. No one with Berkeley before him, and accepting Berkeley’s negative results, could answer this question in Locke’s simple way by making the primitive consciousness report itself as an effect of the operation of body. To do so is to transfer a later and highly complex form of consciousness, whose growth has to be traced, into the earlier and simple form from which the growth is supposed to begin. This, upon the supposition that the process of consciousness by which conceptions are formed is a series of psychical events--a supposition on which the whole method of empirical psychology rests--is in principle the same false procedure as that which we have imagined in the case of a geologist above.
But the question is whether, by any procedure not open to this condemnation, the theory could seem to do what it professes to do--explain thought or ‘cognition by means of conceptions’ as something which happens in sequence upon previous psychical events. Does it not, however stated, carry with it an implication of the supposed later state in the earlier, and is it not solely in virtue of this implication that it seems to be able to trace the genesis of the later? No one has pursued it with stricter promises, or made a fairer show of being faithful to them, than Hume. He will begin with simple feeling, as first experienced by the individual--unqualified by complex conceptions, physical or metaphysical, of matter or of mind--and trace the process by which it generates the ‘ideas of philosophical relation.’ If it can be shown, as we believe it can be, that, even when thus pursued, its semblance of success is due to the fact that, by interpreting the earliest consciousness in terms of the latest, it puts the latter in place of the former, some suspicion may perhaps be created that a natural history of self-consciousness, and of the conceptions by which it makes the world its own, is impossible, since such a history must be of events, and self-consciousness is not reducible to a series of events; being already at its beginning formally, or potentially, or implicitly all that it becomes actually or explicitly in developed knowledge.
It only seems to do so by assuming the ‘fiction’ it has to account for; by assuming that impression represents a real world. 201. If Hume were consistent in allowing no other determination to the impression than that of its having the maximum of vivacity, or to other modes of consciousness than the several degrees of their removal from this maximum, he would certainly have avoided the difficulties which attend Locke’s use of the metaphor of impression, while at the same time he would have missed the convenience, involved in this use, of being able to represent the primitive consciousness as already a recognition of a thing impressing it, and thus an ‘idea of a quality of body.’ But at the outset he remarks that ‘the examination of our sensations’ (_i.e._ our impressions of sensation) ‘belongs more to anatomists and natural philosophers than to moral,’ and that for that reason he shall begin not with them but with ideas. [1] Now this virtually means that he will begin, indeed, with the feelings he finds in himself, but with these as determined by the notion that they are results of something else, of which the nature is not for the present explained.
Thus, while he does not, like Locke, identify our earliest consciousness with a rough and ready physical theory of its cause, he gains the advantage of this identification in the mind of his reader, who from sensation, thus apparently defined, transfers a definiteness to the ideas and secondary impressions as derived from it, though in the sequel the theory turns out, if possible at all, to be at best a remote result of custom and association. We shall see this more clearly if we look back to the general account of impressions and ideas quoted above. ‘An impression first strikes upon the senses and makes us perceive pleasure or pain, of which a copy is taken by the mind,’ called an idea. Now if we set aside the notion of a body making impact upon a sensuous, and through it upon a mental, tablet, pleasure or pain _is_ the impression, which, again, is as much or as little in the mind as the idea. Thus the statement might be re-written as follows:--‘Pleasure or pain makes the mind perceive pleasure or pain, of which a copy is taken by the mind.’
This, of course, is nonsense; but between this nonsense and the plausibility of the statement as it stands, the difference depends on the double distinction understood in the latter--the distinction _(a)_ between the producing cause of the impression and the impression produced; and _(b)_ between the impression as produced on the senses, and the idea as preserved by the mind. This passage, as we shall see, is only a sample of many of the same sort. Throughout, however explicitly Hume may give warning that the difference between impression and idea is only one of liveliness, however little he may scruple in the sequel to reduce body and mind alike to the succession of feelings, his system gains the benefit of the contrary assumption which the uncritical reader is ready to make for him.
Text from Project Gutenberg, public domain in the United States.