A Treatise of Human Nature · David Hume
GENERAL INTRODUCTION TO VOL. I.
Thus in order that any definite ‘object’ of experience may exist for us, our feelings must have ceased to be what according to Hume they are in themselves. They cease to be so in virtue of the presence to them of the Ego, in common relation to which they become related to each other as mutually qualified members of a permanent system--a system which at first for the individual consciousness exists only as a forecast or in outline, and is gradually realized and filled up with the accession of experience. It is quite true that nothing more than the reference to such a system, already necessary to constitute the simplest object of experience, is involved in that interpretation of every event as a changed appearance of an unchanging order, and therefore to be accounted for, which we call inference to a cause or the inference of necessary connection; or, again, in the identification of the event, the determination of its particular nature by the discovery of its particular cause. [1] Above, pars. 285 & 286. [2] P. 436 and elsewhere. [Book I, part III., sec. XII.] How his doctrine might have been developed. Its actual outcome.
315. The supposed difference then between immediate and mediate cognition is no absolute difference. It is not a difference between experience and a process that goes beyond experience, or between an experience unregulated by a conception of a permanent system and one that is so regulated. It lies merely in the degree of fullness and articulation which that conception has attained. If this had been what Hume meant to convey in his assimilation of inference to perception, he would have gone far to anticipate the result of the enquiry which Kant started. And this is what he might have come to mean if, instead of playing fast and loose with ‘impression’ and ‘object,’ using each as plausibility required on the principle of accommodation to the ‘vulgar,’ he had faced the consequence of his own implicit admission, that every perception of an object as identical is a ‘fiction’ in which we go beyond present feeling. As it is, his ‘scepticism with regard to the senses’ goes far enough to empty their ‘reports’ of the content which the ‘vulgar’ ascribe to them, and thus to put a breach between sense and the processes of knowledge, but not far enough to replace the ‘sensible thing’ by a function of reason.
In default of such replacement, there was no way of filling the breach but to bring back the vulgar theory under the cover of habits and ‘tendencies to feign,’ which all suppose a ready-made knowledge of the sensible thing as their starting-point. Hence the constant contradiction, which it is our thankless task to trace, between his solution of the real world into a succession of feelings and the devices by which he sought to make room in his system for the actual procedure of the physical sciences. Conspicuous among these is his allowance of that view of relation in the way of cause and effect as an objective reality, which is represented by his definition of it as a ‘philosophical relation.’ It is in the sense represented by that definition that his doctrine has been understood and retained by subsequent formulators of inductive logic; but on examining it in the light of his own statements we have found that the relation, as thus defined, is not that which his theory required, and as which to represent it is the whole motive of his disquisition on the subject. It is not a sequence of impression upon impression, distinguished merely by its constancy; nor a sequence of idea upon impression, distinguished merely by that transfer of liveliness to the idea which arises from the constancy of its sequence upon the impression. It is a relation between ‘objects’ of which each is what it is only as ‘an instance of a species’ that exists continuously, and therefore in distinction from our ‘perishing impressions,’ according to a regular order of ‘contiguity and succession.’ As such existence and order are by Hume’s own showing no possible impressions, and by consequence no possible ideas, so neither are the ‘objects’ which derive their whole character from them.
No philosophical relation admissible with Hume that is not derived from a natural one. 316. It may be said, however, that wherever Hume admits a definition purporting to be of a ‘philosophical relation,’ he does so only as an accommodation, and under warning that every such relation is ‘fictitious’ except so far as it is equivalent to a natural one; that according to his express statement ‘it is only so far as causation is a _natural_ relation, and produces an union among our ideas, that we are able to reason upon it or draw any inference from it’; [1] and that therefore it is only by his definition of it as a ‘natural relation’ that he is to be judged. Such a vindication of Hume would be more true than effective. That with him the ‘philosophical’ relation of cause and effect is ‘fictitious,’ with all the fictitiousness of a ‘continued existence distinct from perceptions,’ is what it has been the object of the preceding paragraphs to show. But the fictitiousness of a relation can with him mean nothing else than that, instead of having an idea of it, we have only a ‘tendency to suppose’ that we have such an idea. Thus the designation of the philosophical relation of cause and effect carries with it two conditions, one negative, the other positive, on the observance of which the logical value of the designation depends.
The ‘tendency to suppose’ must _not_ after all be itself translated into the idea which it is to replace; and it _must_ be accounted for as derived from a ‘natural relation’ which is not fictitious. That the negative condition is violated by Hume, we have sufficiently seen. He treats the ‘philosophical relation’ of cause and effect, in spite of the ‘fictions’ which it involves, not as a name for a tendency to suppose that we have an idea which we have not, but as itself a definite idea on which he founds various ‘rules for judging what objects are really so related and what are not’. [2] That the positive condition is violated also--that the ‘natural relation’ of cause and effect, according to the sense in which his definition of it is meant to be understood, already itself involves ‘fictions,’ and only for that reason is a possible source of the ‘philosophical’--is what we have next to show. [1] P. 394. [Book I, part III., sec. VII.] [2] Part III. § 15. Examination of his account of cause and effect as ‘natural relation’.
317. That definition, it will be remembered, runs as follows: ‘A cause is an object precedent and contiguous to another, and so united with it in the imagination that the idea of the one determines the mind to form the idea of the other, and the impression of the one to form a more lively idea of the other.’ Now, as has been sufficiently shown, the object of an idea with Hume can properly mean nothing but the impression from which the idea is derived, which again is only the livelier idea, even as the idea is the fainter impression. The idea and the object of it, then, only differ as different stages in the vivacity of a feeling. [1] It must be remembered, further, in regard to the ‘determination of the mind’ spoken of in the definition, that the ‘mind’ according to Hume is merely a succession of impressions and ideas, and that its ‘determination’ means no more than a certain habitualness in this succession. Deprived of the benefit of ambiguous phraseology, then, the definition would run thus: ‘A cause is a lively feeling immediately precedent to another, [2] and so united with it that when either of the two more faintly recurs, the other follows with like faintness, and when either occurs with the maximum of liveliness the other follows with less, but still great, liveliness.’ Thus stated, the definition would correspond well enough to the process by which Hume arrives at it, of which the whole drift, as we have seen, is to merge the so-called objective relation of cause and effect, with the so-called inference from it, in the mere habitual transition from one feeling to another. But it is only because not thus stated, and because the actual statement is understood to carry a meaning of which Hume’s doctrine does not consistently admit, that it has a chance of finding acceptance.
Its plausibility depends on ‘object’ and ‘mind’ and ‘determination’ being understood precisely in the sense in which, according to Hume, they ought not to be understood, so that it shall express not a sequence of feeling upon feeling, as this might be for a merely feeling subject, but that permanent relation or law of nature which to a subject that thinks upon its feelings, and only to such a subject, their sequence constitutes or on which it depends. [1] See above, paragraphs 195 and 208. Cf. also, among other passages, one in the chapter now under consideration (p. 451) [Book I, part III., sec. XIV.]--‘Ideas always represent their _objects or impressions_.’ [2] The phrase ‘immediately precedent’ would seem to convey Hume’s meaning better than his own phrase ‘precedent and contiguous.’ Contiguity _in space_ (which is what we naturally understand by ‘contiguity,’ when used absolutely) he could not have deliberately taken to be necessary to constitute the relation of cause and effect, since the impressions so related, as he elsewhere shows, may often not be in space at all. Double meaning of natural relation. How Hume turns it to account.
318. It is this essential distinction between the sequence of feeling upon feeling for a sentient subject and the relation which to a thinking subject this sequence constitutes--a distinction not less essential than that between the conditions, through which a man passes in sleep, as they are for the sleeping subject himself, and as they are for another thinking upon them--which it is the characteristic of Hume’s doctrine of natural relation in all its forms to disguise. Only in virtue of the presence to feelings of a subject, which distinguishes itself from them, do they become related objects. Thus, with Hume’s exclusion of such a subject, with his reduction of mind and world alike to the succession of feelings, relations and ideas of relation logically disappear. But by help of the phrase ‘natural relation,’ covering, as it does, two wholly different things--the involuntary sequence of one feeling upon another, and that determination of each by the other which can only take place for a synthetic self-consciousness--he is able on the one hand to deny that the relations which form the framework of knowledge are more than sequences of feeling, and on the other to clothe them with so much of the real character of relations as qualifies them for ‘principles of union among ideas.’ Thus the mere occurrence of similar feelings is with him already that relation in the way of resemblance, which in truth only exists for a subject that can contemplate them as permanent objects. In like manner the succession of feelings, which can only constitute time for a subject that contrasts the succession with its own unity, and which, if ideas were feelings, would exclude the possibility of an idea of time, is yet with him indifferently time and the idea of time, though ideas are feelings and there is no ‘mind’ but their succession.
If an effect is merely a constantly observed sequence, how can an event be an effect the first time it is observed? Hume evades this question; 319. The fallacy of Hume’s doctrine of causation is merely an aggravated form of that which has generally passed muster in his doctrine of time. If time, because a relation between feelings, can be supposed to survive the exclusion of a thinking self and the reduction of the world and mind to a succession of feelings, the relation of cause and effect has only to be assimilated to that of time in order that its incompatibility with the desired reduction may disappear, The great obstacle to such assimilation lies in that opposition to the mere sequence of feelings which causation as ‘matter of fact’--as that in discovering which we ‘discover the real existence and relations of objects’--purports to carry with it. Why do we set aside our usual experience as delusive in contrast with the exceptional experience of the laboratory--why do we decide that an event which has seemed to happen cannot really have happened, because under the given conditions no adequate cause of it could have been operative--if the relation of cause and effect is itself merely a succession of seemings, repeated so often as to leave behind it a lively expectation of its recurrence? This question, once fairly put, cannot be answered: it can only be evaded. It is Hume’s method of evasion that we have now more particularly to notice.
Still, he is a long way off the Inductive Logic, which supposes an objective sequence. 320. In its detailed statement it is very different from the method adopted in those modern treatises of Logic which, beginning with the doctrine that facts are merely feelings in the constitution of which thought has no share, still contrive to make free use in their logical canon of the antithesis between the real and apparent. The key to this modern method is to be found in its ambiguous use of the term ‘phenomenon,’ alike for the feeling as it is felt, ‘perishing’ when it ceases to be felt, and for the feeling as it is for a thinking subject--a qualifying and qualified element in a permanent world. Only if facts were ‘phenomena’ in the former sense would the antithesis between facts and conceptions be valid; only if ‘phenomena’ are understood in the latter sense can causation be said to be a law of phenomena. So strong, however, is the charm which this ambiguous term has exercised, that to the ordinary modern logician the question above put may probably seem unmeaning. ‘The appearance,’ he will say, ‘which we set aside as delusive does not consist in any of the reports of the senses--these are always true--but in some false supposition in regard to them due to an insufficient analysis of experience, in some reference of an actual sensation to a group of supposed possibilities of sensation, called a “thing,” which are either unreal or with which it is not really connected. The correction of the false appearance by a discovery of causation is the replacement of a false supposition, as to the possibility of the antecedence or sequence of one feeling to another, by the discovery, through analysis of experience, of what feelings do actually precede and follow each other. It implies no transition from feelings to things, but only from a supposed sequence of feelings to the actual one. Science in its farthest range leaves us among appearances still. It only teaches us what really appears.’
Can the principle of uniformity of nature be derived from sequence of feelings? 321. Now the presupposition of this answer is the existence of just that necessary connexion as between appearances, just that objective order, for which, because it is not a possible ‘impression or idea,’ Hume has to substitute a blind propensity produced by habit. Those who make it, indeed, would repel the imputation of believing in any ‘necessary connexion,’ which to them represents that ‘mysterious tie’ in which they vaguely suppose ‘metaphysicians’ to believe. They would say that necessary connexion is no more than uniformity of sequence. But sequence of what? Not of feelings as the individual feels them, for then there would be no perfect uniformities, but only various degrees of approximation to uniformity, and the measure of approximation in each case would be the amount of the individual’s experience in that particular direction. The procedure of the inductive logician shows that his belief in the uniformity of a sequence is irrespective of the number of instances in which it has been experienced.
A single instance in which one feeling is felt after another, if it satisfy the requirements of the ‘method of difference,’ _i.e._ if it show exactly what it is that precedes and what it is that follows in that instance, suffices to establish a uniformity of sequence, on the principle that what is fact once is fact always. Now a uniformity that can be thus established is in the proper sense necessary. Its existence is not contingent on its being felt by anyone or everyone. It does not come into being with the experiment that shows it. It is felt because it is real, not real because it is felt. It may be objected indeed that the principle of the ‘uniformity of nature,’ the principle that what is fact once is fact always, itself gradually results from the observation of facts which are feelings, and that thus the principle which enables us to dispense with the repetition of a sensible experience is itself due to such repetition. The answer is, that feelings which are conceived as facts are already conceived as constituents of a nature. The same presence of the thinking subject to, and distinction of itself from, the feelings, which renders them knowable _facts_, renders them members of a world which is one throughout its changes. In other words, the presence of facts from which the uniformity of nature, as an abstract rule, is to be inferred, is already the consciousness of that uniformity _in concreto_.
With Hume the only uniformity is in expectation, as determined by habit; but strength of such expectation must vary indefinitely. 322. Hume himself makes a much more thorough attempt to avoid that pre-determination of feelings by the conception of a world, of things and relations, which is implied in the view of them as permanent facts. He will not, if he can help it, so openly depart from the original doctrine that thought is merely weaker sense. Such conceptions as those of the uniformity of nature and of reality, being no possible ‘impressions or ideas,’ he only professes to admit in a character wholly different from that in which they actually govern inductive philosophy. Just as by reality he understands not something to which liveliness of feeling may be an index, but simply that liveliness itself, and by an inferred or believed reality a feeling to which this liveliness has been communicated from one that already has it; so he is careful to tell us ‘that the supposition that the future resembles the past is derived entirely from habit, by which we are determined to expect for the future the same train of objects to which we have been accustomed’. [1] The supposition then _is_ this ‘determination,’ this ‘propensity,’ to expect.
Any ‘idea’ derived from the propensity can only be the propensity itself at a fainter stage; and between such a propensity and the conception of ‘nature,’ whether as uniform or otherwise, there is a difference which only the most hasty reader can be liable to ignore. But if by any confusion an expectation of future feelings, determined by the remembrance of past feelings, could be made equivalent to any conception of nature, it would not be of nature as uniform. As is the ‘habit’ which determines the expectation, such must be the expectation itself; and as have been the sequences of feeling in each man’s past, such must be the habit which results from them. Now no one’s feelings have always occurred to him in the same relative order. There may be some pairs of feelings of which one has always been felt before the other and never after it, and between which there has never been an intervention of a third--although (to take Hume’s favourite instance) even the feeling of heat may sometimes precede the sight of the flame--and in these cases upon occurrence of one there will be nothing to qualify the expectation of the other. But just so far as there are exceptions in our past experience to the immediate sequence of one feeling upon another, must there be a qualification of our expectation of the future, if it be undetermined by extraneous conceptions, with reference to those particular feelings.
In such an expectation, in an expectation made up of such expectations, there would be nothing to serve the purpose which the conception of the uniformity of nature actually serves in inductive science. It could never make us believe that a feeling felt before another--as when the motion of a bell is seen before the sound of it has been heard--represents the real antecedent. It could never set us upon that analysis of our experience by which we seek to get beyond sequences that are merely usual, and admit of indefinite exceptions, to such as are invariable; upon that ‘interrogation of nature’ by which, on the faith that there is a uniformity if only we could find it out, we wrest from her that confession of a law which she does not spontaneously offer. The fact that some sequences of feeling have been so uniform as to result in unqualified expectations (if it be so) could of itself afford no motive for trying to compass other expectations of a like character which do not naturally present themselves. Nor could there be anything in the appearance of an exception to a sequence, hitherto found uniform, to lead us to change our previous expectation for one which shall not be liable to such modification. The previous expectation would be so far weakened, but there is nothing in the mere weakening of our expectations that should lead to the effort to place them beyond the possibility of being weakened. Much less could the bundle of expectations come to conceive themselves as one system so as that, through the interpretation of each exception to a supposed uniformity of sequence as an instance of a real one, the changes of the parts should prove the unchangeableness of the whole.
Nor does Hume in so many words allow that it is otherwise, but meanwhile though the expectation itself is not openly tampered with, the remembrance that determines it is so. This is being taken to be that, which it cannot be unless ideas unborrowed from impressions are operative in and upon it. It is being regarded, not as the recurrence of a multitude of feelings with a liveliness indefinitely less than that in virtue of which they are called impressions of sense, and indefinitely greater than that in virtue of which they are called ideas of imagination, but as the recognition of a world of experience, one, real and abiding. An expectation determined by such remembrance is governed by the same ‘fictions’ of identity and continued existence which are the formative conditions of the remembrance. Expectation and remembrance, in fact, are one and the same intellectual act, one and the same reference of feelings, given in time, to an order that is not in time, distinguished according to the two faces which, its ‘matter’ being in time, it has to present severally to past and future. The remembrance is the measure of the expectation, but as the remembrance carries with it the notion of a world whose existence does not depend on its being remembered, and whose laws do not vary according to the regularity or looseness with which our ideas are associated, so too does the expectation, and only as so doing becomes the mover and regulator of ‘inference from the known to the unknown.’
Taken strictly, indeed, his doctrine implies that a belief in a miracle is a contradiction in terms. An event is not regarded as miraculous unless it is regarded as a ‘transgression of a law of nature by a particular volition of the Deity or by the interposition of some invisible agent’ (page 93, note 1); but it could not transgress a law of nature in Hume’s sense unless it were so inconsistent with the habitual association of ideas as that it could not be believed. Hume’s only consistent way of attacking miracles, then, would have been to show that the events in question, as _miraculous_, had never been believed. Having been obliged to recognize the belief in their having happened, he is open to the retort ‘ad hominem’ that according to his own showing the belief in the events constitutes their reality. Such a retort, however, would be of no avail in the theological interest, which requires not merely that the events should have happened but that they should have been _miraculous_, _i.e._ ‘transgressions of a law of nature by a particular volition of the Deity.’
Text from Project Gutenberg, public domain in the United States.