A Treatise of Human Nature / Being an Attempt to Introduce the Experimental Method Into Moral Subjects; and Dialogues Concerning Natural Religion

by David Hume

309. That it is gratuitous we may readily admit, but only because a recognition of the function of the Ego in the primary constitution of the qualified individual object—this pen or this paper—renders it superfluous. To the philosophy, however, in which Hume was bred, the perception of a qualified object was simply a feeling. No intellectual synthesis of successive feelings was recognized as involved in it. It was only so far as the dependence of the feeling on our organs, in the absence of any clear distinction between feeling and felt thing, seemed to imply a dependent and broken existence of the thing, that any difficulty arose—a difficulty met by the supposition that the felt thing, whose existence was thus broken and dependent, represented an unfelt and permanent thing of which it is a copy or effect. To the Berkeleian objections, already fatal to this supposition, Hume has his own to add, viz. that we can have no idea of relation in the way of cause and effect except as between objects which we have observed, and therefore can have no idea of it as existing between a perception and an object of which we can only say that it is not a perception. Is all existence then ‘broken and dependent’? That is the ‘sceptical’ conclusion which Hume professes to adopt—subject, however, to the condition of accounting for the contrary supposition (without which, as he has to admit, we could not think or speak, and which alone gives a meaning to his own phraseology about impressions and ideas) as a fiction of the imagination. He does this, as we have seen, by tracing a series of contradictions, with corresponding hypotheses invented, either instinctively or upon reflection, in order to escape the uneasiness which they cause, all ultimately due to our mistaking similar successive feelings for an identical object. Of such an object, then, we must have an idea to begin with, and it is an object permanent throughout a variation of time, which means a succession of feelings; in other words, it is a felt thing, as distinct from feelings but to which feelings are referred as its qualities. Thus the most primary perception—that in default of which Hume would have no reality to oppose to fiction, nor any point of departure for the supposed construction of fictions—already implies that transformation of feelings into changing relations of a thing which, preventing any incompatibility between the perpetual brokenness of the feeling and the permanence of the thing, ‘eludes’ by anticipation all the contradictions which, according to Hume, we only ‘elude’ by speaking as if we had ideas that we have not.

Yet they are not possible ideas, because copied from no impressions.

310. ‘Ideas that we have not;’ for no one of the fictions by which we elude the contradictions, nor indeed any one of the contradictory judgments themselves, can be taken to represent an ‘idea’ according to Hume’s account of ideas. He allows himself indeed to speak of our having ideas of identical objects, such as this table while I see or touch it—though in this case, as has been shown, either the object is not identical or the idea of it cannot be copied from an impression—and of our transferring this idea to resembling but interrupted perceptions. But the supposition to which the contradiction involved in this transference gives rise—the supposition that the perception continues to exist when it is not perceived—is shown by the very statement of it to be no possible copy of an impression. Yet according to Hume it is a ‘belief,’ and a belief is ‘a lively idea associated with a present impression.’ What then is the impression and what the associated idea? ‘As the propensity to feign the continued existence of sensible objects arises from some lively impressions of the memory, it bestows a vivacity on that fiction; or, in other words, makes us believe the continued existence of body’. [1] Well and good: but this only answers the first part of our question. It tells us what are the impressions in the supposed case of belief, but not what is the associated idea to which their liveliness is communicated. To say that it arises from a propensity to feign, strong in proportion to the liveliness of the supposed impressions of memory, does not tell us of what impression it is a copy. Such a propensity indeed would be an ‘impression of reflection,’ but the fiction itself is neither the propensity nor a copy of it. The only possible supposition left for Hume would be that it is a ‘compound idea;’ but what combination of ‘perceptions’ can amount to the existence of perceptions when they are not perceived?

[1] P. 496. [Book I, part IV., sec. II.]

Comparison of present experience with past, which yields relation of cause and effect, pre-supposes judgment of identity;

311. From this long excursion into Hume’s doctrine of relation in the way of identity—having found him admitting explicitly that it is only by a ‘fiction of the imagination’ that we identify this table as now seen with this table as seen an hour ago, and implicitly that the same fiction is involved in the perception of this table as an identical object even when hand or eye is kept upon it, while yet he says not a word to vindicate the possibility of such a fiction for a faculty which can merely reproduce and combine ‘perishing impressions’—we return to consider its bearing upon his doctrine of relation in the way of cause and effect. According to him, as we saw, [1] that relation, ‘considered as a philosophical’ one, is founded on a comparison of present experience with past, in the sense that we regard an object, precedent and contiguous to another, as its cause when all like objects have been found similarly related. The question then arises whether the experiences compared—the present and the past alike—do not involve the fiction of identity along with the whole family of other fictions which Hume affiliates to it? Does the relation of precedence and sequence, which, if constant, amounts to that of cause and effect, merely mean precedence and sequence of two feelings, indefinitely like an indefinite number of other feelings that have thus the one preceded and the other followed; or is it a relation between one qualified thing or definite fact always the same with itself, and another such thing or fact always the same with itself? The question carries its own answer. If in the definition quoted Hume used the phrase ‘all like objects’ instead of the ‘same object,’ in order to avoid the appearance of introducing the ‘fiction’ of identity into the definition of cause, the device does not avail him much. The effect of the ‘like’ is neutralized by the ‘all.’ A uniform relation is impossible except between objects of which each has a definite identity.

[1] Above, pars. 298 and 299.

… without which there could be no recognition of an object as one observed before.

312. When Hume has to describe the experience which gives the idea of cause and effect, he virtually admits this. ‘The nature of experience,’ he tells us, ‘is this. We remember to have had frequent instances of the existence of one species of objects, and also remember that the individuals of another species of objects have always attended them, and have existed in a regular order of contiguity and succession with regard to them. Thus we remember to have seen that species of object we call flame, and to have felt that species of sensation we call heat. We likewise call to mind their constant conjunction in all past instances. Without any farther ceremony we call the one cause, and the other effect, and infer the existence of the one from the other’. [1] It appears, then, that upon experiencing certain sensations of sight and touch, we recognize each as ‘one of a species of objects’ which we remember to have observed in certain constant relations before. In virtue of the recognition the sensations become severally this flame and this heat; and in virtue of the remembrance the objects thus recognized are held to be related in the way of cause and effect. Now it is clear that though the recognition takes place upon occasion of a feeling, the object recognized—this flame or this heat—is by no means the feeling as a ‘perishing existence.’ Unless the feeling were taken to represent a thing, conceived as permanently existing under certain relations and attributes—in other words, unless it were identified by thought—it would be no definite object, not this flame or this heat, at all. The moment it is named, it has ceased to be a feeling and become a felt thing, or, in Hume’s language, an ‘individual of a species of objects.’ And just as the present ‘perception’ is the recognition of such an individual, so the remembrance which determines the recognition is one wholly different from the return with lessened liveliness of a feeling more strongly felt before. According to Hume’s own statement, it consists in recalling ‘frequent instances of the existence of a species of objects.’ It is remembrance of an experience in which every feeling, that has been attended to, has been interpreted as a fresh appearance of some qualified object that ‘exists’ throughout its appearances—an experience which for that reason forms a connected whole. If it were not so, there could be no such comparison of the relations in which two objects are now presented with those in which they have always been presented, as that which according to Hume determines us to regard them as cause and effect. The condition of our so regarding them is that we suppose the objects now presented to be the same with those of which we have had previous experience. It is only on supposition that a certain sensation of sight is not merely like a multitude of others, but represents the same object as that which I have previously known as flame, that I infer the sequence of heat and, when it does follow, regard it as an effect. If I thought that the sensation of sight, however like those previously referred to flame, did not represent the same object, I should not infer heat as effect; and conversely, if, having identified the sensation of sight as representative of flame, I found that the inferred heat was not actually felt, I should judge that I was mistaken in the identification. It follows that it is only an experience of identical, and by consequence related and qualified, objects, of which the memory can so determine a sequence of feelings as to constitute it an experience of cause and effect. Thus the perception and remembrance upon which, according to Hume, we judge one object to be the cause of another, alike rest on the ‘fictions of identity and continued existence.’ Without these no present experience would, in his language, be an instance of an individual of a certain species existing in a certain relation, nor would there be a past experience of individuals of the same species, by comparison with which the constancy of the relation might be ascertained.

[1] P. 388. [Book I, part III., sec. VI.]