Kant begins[21] his proof as follows: "Our apprehension of the manifold of a phenomenon is always successive. The representations of the parts succeed one another. Whether they succeed one another in the object also is a second point for reflection which is not contained in the first."[22] But, before he can continue, the very nature of these opening sentences compels him to consider a general problem which they raise. The distinction referred to between a succession in our apprehensions or representations and a succession in the object implies an object distinct from the apprehensions or representations.
What, then, can be meant by such an object? For prima facie, if we ignore the thing in itself as unknowable, there is no object; there are only representations. But, in that case, what can be meant by a succession in the object? Kant is therefore once more[23] forced to consider the question "What is meant by object of representations?"
although on this occasion with special reference to the meaning of a succession in the object; and the vindication of causality is bound up with the answer. The answer is stated thus:
[21] The preceding paragraph is an addition of the second edition.
[22] B. 234, M. 142.
[23] Cf. A. 104-5, Mah. 198-9, and pp. 178-86 and 230-3.
"Now we may certainly give the name of object to everything, and even to every representation, so far as we are conscious thereof; but what this word may mean in the case of phenomena, not in so far as they (as representations) are objects, but in so far as they only indicate an object, is a question requiring deeper consideration. So far as they, as representations only, are at the same time objects of consciousness, they are not to be distinguished from apprehension, i. e. reception into the synthesis of imagination, and we must therefore say, "The manifold of phenomena is always produced successively in the mind". If phenomena were things in themselves, no man would be able to infer from the succession of the representations of their manifold how this manifold is connected in the object. For after all we have to do only with our representations; how things may be in themselves, without regard to the representations through which they affect us, is wholly outside the sphere of our knowledge. Now, although phenomena are not things in themselves, and are nevertheless the only thing which can be given to us as data for knowledge, it is my business to show what kind of connexion in time belongs to the manifold in phenomena themselves, while the representation of this manifold in apprehension is always successive. Thus, for example, the apprehension of the manifold in the phenomenon of a house which stands before me is successive. Now arises the question, whether the manifold of this house itself is in itself also successive, which of course no one will grant. But, so soon as I raise my conceptions of an object to the transcendental meaning thereof, the house is not a thing in itself, but only a phenomenon, i. e. a representation, the transcendental object of which is unknown. What, then, am I to understand by the question, "How may the manifold be connected in the phenomenon itself (which is nevertheless nothing in itself)?" Here that which lies in the successive apprehension is regarded as representation, while the phenomenon which is given me, although it is nothing more than a complex of these representations, is regarded as the object thereof, with which my conception, drawn from the representations of apprehension, is to agree. It is soon seen that, since agreement of knowledge with the object is truth, we can ask here only for the formal conditions of empirical truth, and that the phenomenon, in opposition to the representations of apprehension, can only be represented as the object of the same, distinct therefrom, if it stands under a rule, which distinguishes it from every other apprehension, and which renders necessary a mode of conjunction of the manifold. That in the phenomenon which contains the condition of this necessary rule of apprehension is the object."[24]
[24] B. 234-6, M. 143-4. Cf. B. 242, M. 147.
This pa.s.sage is only intelligible if we realize the _impa.s.se_ into which Kant has been led by his doctrine that objects, i. e. realities in the physical world, are only representations or ideas. As has already been pointed out,[25] an apprehension is essentially inseparable from a reality of which it is the apprehension. In other words, an apprehension is always the apprehension of a reality, and a reality apprehended, i. e. an object of apprehension, cannot be stated in terms of the apprehension of it. We never confuse an apprehension and its object; nor do we take the temporal relations which belong to the one for the temporal relations which belong to the other, for these relations involve different terms which are never confused, viz.
apprehensions and the objects apprehended. Now Kant, by his doctrine of the unknowability of the thing in itself, has really deprived himself of an object of apprehension or, in his language, of an object of representations. For it is the thing in itself which is, properly speaking, the object of the representations of which he is thinking, i. e. representations of a reality in nature; and yet the thing in itself, being on his view inapprehensible, can never be for him an object in the proper sense, i. e. a reality apprehended. Hence he is only able to state the fact of knowledge in terms of mere apprehensions, or ideas, or representations--the particular name is a matter of indifference--and consequently his efforts to recover an object of apprehension are fruitless. As a matter of fact, these efforts only result in the a.s.sertion that the object of representations consists in the representations themselves related in a certain necessary way. But this view is open to two fatal objections. In the first place, a complex of representations is just not an object in the proper sense, i. e. a reality apprehended. It essentially falls on the subject side of the distinction between an apprehension and the reality apprehended. The _complexity_ of a complex of representations in no way divests it of the character which it has as a complex of _representations_. In the second place, on this view the same terms have to enter at once into two incompatible relations. Representations have to be related successively as our representations or apprehensions--as in fact they are related--and, at the same time, successively or otherwise, as the case may be, as parts of the object apprehended, viz. a reality in nature. In other words, the same terms have to enter into both a subjective and an objective relation, i. e. both a relation concerning us, the knowing subjects, and a relation concerning the object which we know.[26] "A phenomenon in opposition to the representations of apprehension can only be represented as the object of the same, distinct therefrom, if it stands under a rule which distinguishes it from _every other_ apprehension, and renders necessary a mode of conjunction of the manifold."[27] A representation, however, cannot be so related by a rule to another representation, for the rule meant relates to realities in nature, and, however much Kant may try to maintain the contrary, two representations, not being realities in nature, cannot be so related. Kant is in fact only driven to treat rules of nature as relating to representations, because there is nothing else to which he can regard them as relating. The result is that he is unable to justify the very distinction, the implications of which it is his aim to discover, and he is unable to do so for the very reason which would have rendered Hume unable to justify it. Like Hume, he is committed to a philosophical vocabulary which makes it meaningless to speak of relations of objects at all in distinction from relations of apprehensions. It has been said that for Kant the road to objectivity lay through necessity.[28] But whatever Kant may have thought, in point of fact there is no road to objectivity, and, in particular, no road through necessity. No necessity in the relation between two representations can render the relation objective, i. e. a relation between objects. No doubt the successive acts in which we come to apprehend the world are necessarily related; we certainly do not suppose their order to be fortuitous. Nevertheless, their relations are not in consequence a relation of realities apprehended.
[25] pp. 133-4; cf. pp. 180 and 230-1.
[26] Cf. p. 209, note 3, and p. 233.
[27] The italics are mine.
[28] Caird, i. 557.
Kant only renders his own view plausible by treating an apprehension or representation as if it consisted in a sensation or an appearance.
A sensation or an appearance, so far from being the apprehension of anything, is in fact a reality which can be apprehended, of the kind called mental. Hence it can be treated as an object, i. e. something apprehended or presented, though not really as an object in nature. On the other hand, from the point of view of the thing in itself it can be treated as only an apprehension, even though it is an unsuccessful apprehension. Thus, for Kant, there is something which can with some plausibility be treated as an object as well as an apprehension, and therefore as capable of standing in both a subjective and an objective relation to other realities of the same kind.[29]
[29] Cf. pp. 137 and 231.
If we now turn to the pa.s.sage under discussion, we find it easy to vindicate the justice of the criticism that Kant, inconsistently with the distinction which he desires to elucidate, treats the same thing as at once the representation of an object and the object represented.
He is trying to give such an account of "object of representations" as will explain what is meant by a succession in an object in nature, i. e. a phenomenon, in distinction from the succession in our apprehension of it. In order to state this distinction at all, he has to speak of what enters into the two successions as different. "It is my business to show what sort of connexion in time belongs to the _manifold_ in phenomena themselves, while the _representation_ of this manifold in apprehension is always successive."[30] Here an element of the manifold is distinguished from the representation of it. Yet Kant, though he thus distinguishes them, repeatedly identifies them; in other words, he identifies a representation with that of which it is a representation, viz. an element in or part of the object itself. "_Our apprehension_ of the manifold of the phenomenon is always successive.
_The representations_ of the parts succeed one another. Whether _they_ [i. e. _the representations_[31]] succeed one another _in the object_ also, is a second point for reflection.... So far as they [i. e.
phenomena], as representations only, are at the same time objects of consciousness, they are not to be distinguished from apprehension, i. e. reception into the synthesis of imagination, and we must therefore say, _"The manifold of phenomena_ is always produced successively in the mind". If phenomena were things in themselves, no man would be able to infer from the succession of the representations how _this manifold_ is connected _in the object_.... The phenomenon, in opposition to the representations of apprehension, can only be represented as the object of the same, distinct therefrom, if it stands under a rule, which distinguishes _it_ from every _other_ representation and which renders necessary a mode of conjunction of the manifold."[32]
[30] The italics are mine.
[31] This is implied both by the use of "also" and by the context.
[32] The italics are mine.
Since Kant in introducing his vindication of causality thus identifies elements in the object apprehended (i. e. the manifold of phenomena) with the apprehensions of them, we approach the vindication itself with the expectation that he will identify a causal rule, which consists in a necessity in the succession of objects, viz. of events in nature, with the necessity in the succession of our apprehensions of them. This expectation turns out justified. The following pa.s.sage adequately expresses the vindication:
"Let us now proceed to our task. That something happens, i. e. that something or some state comes to be which before was not, cannot be empirically perceived, unless a phenomenon precedes, which does not contain in itself this state; for a reality which follows upon an empty time, and therefore a coming into existence preceded by no state of things, can just as little be apprehended as empty time itself.
Every apprehension of an event is therefore a perception which follows upon another perception. But because this is the case with all synthesis of apprehension, as I have shown above[33] in the phenomenon of a house, the apprehension of an event is thereby not yet distinguished from other apprehensions. But I notice also, that if in a phenomenon which contains an event, I call the preceding state of my perception A, and the following state B, B can only follow A in apprehension, while the perception A cannot follow B but can only precede it. For example, I see a ship float down a stream. My perception of its place lower down follows upon my perception of its place higher up the course of the river, and it is impossible that in the apprehension of this phenomenon the vessel should be perceived first below and afterwards higher up the stream. Here, therefore, the order in the sequence of perceptions in apprehension is determined, and apprehension is bound to this order. In the former example of a house, my perceptions in apprehension could begin at the roof and end at the foundation, or begin below and end above; in the same way they could apprehend the manifold of the empirical perception from left to right, or from right to left. Accordingly, in the series of these perceptions, there was no determined order, which necessitated my beginning at a certain point, in order to combine the manifold empirically. But this rule is always to be found in the perception of that which happens, and it makes the order of the successive perceptions (in the apprehension of this phenomenon) _necessary_."
[33] B. 235-6, M. 143 (quoted p. 279).
"In the present case, therefore, I shall have to derive the _subjective sequence_ of apprehension from the _objective sequence_ of phenomena, for otherwise the former is wholly undetermined, and does not distinguish one phenomenon from another. The former alone proves nothing as to the connexion of the manifold in the object, for it is wholly arbitrary. The latter, therefore [i. e. the objective sequence of phenomena[34]], will consist in that order of the manifold of the phenomenon, according to which the apprehension of the one (that which happens) follows that of the other (that which precedes) _according to a rule_. In this way alone can I be justified in saying of the phenomenon itself, and not merely of my apprehension, that a sequence is to be found therein, which is the same as to say that I cannot arrange my apprehension otherwise than in just this sequence."
[34] The sense is not affected if "the latter" be understood to refer to the connexion of the manifold in the object.
"In conformity with such a rule, therefore, there must exist in that which in general precedes an event the condition of a rule, according to which this event follows always and necessarily, but I cannot conversely go back from the event, and determine (by apprehension) that which precedes it. For no phenomenon goes back from the succeeding point of time to the preceding point, although it does certainly relate to _some preceding point of time_; on the other hand, the advance from a given time to the determinate succeeding time is necessary. Therefore, because there certainly is something which follows, I must relate it necessarily to something else in general, which precedes, and upon which it follows in conformity with a rule, that is necessarily, so that the event, as the conditioned, affords certain indication of some condition, while this condition determines the event."
"If we suppose that nothing precedes an event, upon which this event must follow in conformity with a rule, all sequence of perception would exist only in apprehension, i. e. would be merely subjective, but it would not thereby be objectively determined which of the perceptions must in fact be the preceding and which the succeeding one. We should in this manner have only a play of representations, which would not be related to any object, i. e. no phenomenon would be distinguished through our perception in respect of time relations from any other, because the succession in apprehension is always of the same kind, and so there is nothing in the phenomenon to determine the succession, so as to render a certain sequence objectively necessary.
I could therefore not say that in the phenomenon two states follow each other, but only that one apprehension follows on another, a fact which is merely _subjective_ and does not determine any object, and cannot therefore be considered as knowledge of an object (not even in the phenomenon)."
"If therefore we experience that something happens, we always thereby presuppose that something precedes, on which it follows according to a rule. For otherwise, I should not say of the object, that it follows, because the mere sequence in my apprehension, if it is not determined by a rule in relation to something preceding, does not justify the a.s.sumption of a sequence in the object. It is therefore always in reference to a rule, according to which phenomena are determined in their sequence (i. e. as they happen) by the preceding state, that I make my subjective synthesis (of apprehension) objective, and it is solely upon this presupposition that even the experience of something which happens is possible."[35]
[35] B. 236-41, M. 144-6.
The meaning of the first paragraph is plain. Kant is saying that when we reflect upon the process by which we come to apprehend the world of nature, we can lay down two propositions. The first is that the process is equally successive whether the object apprehended be a succession in nature or a coexistence of bodies in s.p.a.ce, so that the knowledge that we have a succession of apprehensions would not by itself enable us to decide whether the object of the apprehensions is a sequence or not. The second proposition is that, nevertheless, there is this difference between the succession of our apprehensions where we apprehend a succession and where we apprehend a coexistence, that in the former case, and in that only, the succession of our apprehensions is irreversible or, in other words, is the expression of a rule of order which makes it a necessary succession. So far we find no mention of causality, i. e. of a necessity of succession in objects, but only a necessity of succession in our apprehension of them. So far, again, we find no contribution to the problem of explaining how we distinguish between successive perceptions which are the perceptions of an event and those which are not. For it is reasonable to object that it is only possible to say that the order of our perceptions is irreversible, if and because we already know that what we have been perceiving is an event, and that therefore any attempt to argue from the irreversibility of our perceptions to the existence of a sequence in the object must involve a [Greek: hysteron proteron]. And it is clear that, if irreversibility in our perceptions were the only irreversibility to which appeal could be made, even Kant would not have supposed that the apprehension of a succession was reached through belief in an irreversibility.
The next paragraph, of which the interpretation is difficult, appears to introduce a causal rule, i. e. an irreversibility in objects, by identifying it with the irreversibility in our perceptions of which Kant has been speaking. The first step to this identification is taken by the a.s.sertion: "In the present case, therefore, I shall have to derive the subjective sequence of perceptions from the objective sequence of phenomena.... The latter will consist in the order of the _manifold of the phenomenon_, according to which _the apprehension_ of the one (that which happens) follows that of the other (that which precedes) according to a rule."[36] Here Kant definitely implies that an objective sequence, i. e. an order or sequence of the _manifold_ of a phenomenon, consists in a sequence of _perceptions or apprehensions_ of which the order is necessary or according to a rule; in other words, that a succession of perceptions in the special case where the succession is necessary is a succession of events perceived.[37] This implication enables us to understand the meaning of the a.s.sertion that "we must therefore derive the subjective sequence of perceptions from the objective sequence of phenomena", and to see its connexion with the preceding paragraph. It means, "in view of the fact that in all apprehensions of a succession, and in them alone, the sequence of perceptions is irreversible, we are justified in saying that a given sequence of perceptions is the apprehension of a succession, if we know that the sequence is irreversible; in that case we must be apprehending a real succession, for an irreversible sequence of perceptions _is_ a sequence of events perceived." Having thus implied that irreversibility of perceptions const.i.tutes them events perceived, he is naturally enough able to go on to speak of the irreversibility of perceptions as if it were the same thing as an irreversibility of events perceived, and thus to bring in a causal rule. "In this way alone [i. e. only by deriving the subjective from the objective sequence] can I be justified in saying of the phenomenon itself, and not merely of my apprehension, that a sequence is to be found therein, _which is the same as to say_ that I cannot _arrange_ my apprehension otherwise than in just this sequence. In conformity with _such a rule_, therefore, there must exist in that which in general precedes _an event_ the condition of a rule, according to which _this event follows always and necessarily_."[38] Here the use of the word "arrange"[39] and the statement about the rule in the next sentence imply that Kant has now come to think of the rule of succession as a causal rule relating to the objective succession. Moreover, if any doubt remains as to whether Kant really confuses the two irreversibilities or necessities of succession, it is removed by the last paragraph of the pa.s.sage quoted. "If therefore we experience that something happens, we always thereby presuppose that something precedes on which _it_ follows according to a rule. For otherwise I should not say of the object that _it_ follows; because the mere succession of my apprehension, if _it_ is not determined by a rule in relation to something preceding, does not justify the a.s.sumption of a succession in the object. It is therefore always in reference to a rule, according to which _phenomena_ are determined in their sequence (i. e. as they happen) by the preceding state, that I make my subjective sequence (of apprehension) objective."[40] The fact is simply that Kant _must_ identify the two irreversibilities, because, as has been pointed out, he has only one set of terms to be related as irreversible, viz. the elements of the manifold, which have to be, from one point of view, elements of an object and, from another, representations or apprehensions of it.
[36] The italics are mine. "According to which" does not appear to indicate that the two orders referred to are different.
[37] Cf. B. 242 fin., M. 147 fin.
[38] The italics are mine
[39] _Anstellen._
[40] The italics are mine.
As soon, therefore, as the real nature of Kant"s vindication of causality has been laid bare, it is difficult to describe it as an argument at all. He is anxious to show that in apprehending A B as a real or objective succession we presuppose that they are elements in a causal order of succession. Yet in support of his contention he points only to the quite different fact that where we apprehend a succession A B, we think of the _perception_ of A and the _perception_ of B as elements in a necessary but subjective succession.
Before we attempt to consider the facts with which Kant is dealing, we must refer to a feature in Kant"s account to which no allusion has been made. We should on the whole expect from the pa.s.sage quoted that, in the case where we regard two perceptions A B as necessarily successive and therefore as const.i.tuting an objective succession, the necessity of succession consists in the fact that A is the cause of B.
This, however, is apparently not Kant"s view; on the contrary, he seems to hold that, in thinking of A B as an objective succession, we presuppose not that A causes B, but only that the state of affairs which precedes B, and which therefore includes A, contains a cause of B, the coexistence or ident.i.ty of this cause with A rendering the particular succession A B necessary. "Thus [if I perceive that something happens] it arises that there comes to be an order among our representations in which the present (so far as it has taken place) points to some preceding state as a correlate, _though a still undetermined correlate_,[41] of this event which is given, and this correlate relates to the event by determining the event as its consequence, and connects the event with itself necessarily in the series of time."[42]
[41] The italics are mine.
[42] B. 244, M. 148. Cf. B. 243, M. 148 (first half) and B.
239, M. 145 (second paragraph). The same implication is to be found in his formulation of the rule involved in the perception of an event, e. g. "In conformity with such a rule, there must exist in that which in general precedes an event, the condition of a rule, according to which this event follows always and necessarily." Here the condition of a rule is the necessary antecedent of the event, whatever it may be.
The fact is that Kant is in a difficulty which he feels obscurely himself. He seems driven to this view for two reasons. If he were to maintain that A was necessarily the cause of B, he would be maintaining that all observed sequences are causal, i. e. that in them the antecedent and consequent are always cause and effect, which is palpably contrary to fact. Again, his aim is to show that we become aware of a succession by presupposing the law of causality. This law, however, is quite general, and only a.s.serts that _something_ must precede an event upon which it follows always and necessarily. Hence by itself it palpably gives no means of determining whether this something is A rather than anything else.[43] Therefore if he were to maintain that the antecedent member of an apprehended objective succession must be thought of as its cause, the a.n.a.logy would obviously provide no means of determining the antecedent member, and therefore the succession itself, for the succession must be the sequence of B upon some definite antecedent. On the other hand, the view that the cause of B need not be A only incurs the same difficulty in a rather less obvious form. For, even on this view, the argument implies that in order to apprehend two individual perceptions A B as an objective succession, we must know that A _must_ precede B, and the presupposition that B implies a cause in the state of affairs preceding B in no way enables us to say either that A coexists with the cause, or that it is identical with it, and therefore that it must precede B.
[43] Cf. B. 165, M. 101, where Kant points out that the determination of particular laws of nature requires experience.
Nevertheless, it cannot be regarded as certain that Kant did not think of A, the apprehended antecedent of B, as necessarily the cause of B, for his language is both ambiguous and inconsistent. When he considers the apprehension of a succession from the side of the successive perceptions, he at least tends to think of A B as cause and effect;[44] and it may well be that in discussing the problem from the side of the law of causality, he means the cause of B to be A, although the generality of the law compels him to refer to it as _something_ upon which B follows according to a rule.
[44] He definitely implies this, B. 234, M. 142.
Further, it should be noticed that to allow as Kant, in effect, does elsewhere[45], that experience is needed to determine the cause of B is really to concede that the apprehension of objective successions is _prior to_, and _presupposed by_, any process which appeals to the principle of causality; for if the principle of causality does not by itself enable us to determine the cause of B, it cannot do more than enable us to pick out the cause of B among events known to precede B independently of the principle. Hence, from this point of view, there can be no process such as Kant is trying to describe, and therefore its precise nature is a matter of indifference.
[45] Cf. B. 165, M. 101, where Kant points out that the determination of particular laws of nature requires experience.
We may now turn to the facts. There is, it seems, no such thing as a process by which, beginning with the knowledge of successive apprehensions or representations, of the object of which we are unaware, we come to be aware of their object. Still less is there a process--and it is really this which Kant is trying to describe--by which, so beginning, we come to apprehend these successive representations as objects, i. e. as parts of the physical world, through the thought of them as necessarily related. We may take Kant"s instance of our apprehension of a boat going down stream. We do not first apprehend two perceptions of which the object is undetermined and then decide that their object is a succession rather than a coexistence. Still less do we first apprehend two perceptions or representations and then decide that they are related as successive events in the physical world. From the beginning we apprehend a real sequence, viz. the fact that the boat having left one place is arriving at another; there is no process _to_ this apprehension. In other words, from the beginning we are aware of real elements, viz. of events in nature, and we are aware of them as really related, viz. as successive in nature. This must be so. For if we begin with the awareness of two mere perceptions, we could never thence reach the knowledge that their object was a succession, or even the knowledge that they had an object; nor, so beginning, could we become aware of the perceptions themselves as successive events in the physical world.
For suppose, _per impossibile_, the existence of a process by which we come to be aware of two elements A and B as standing in a relation of sequence in the physical world. In the first place, A and B, with the awareness of which we begin, must be, and be known to be, real or objective, and not perceptions or apprehensions; otherwise we could never come to apprehend them as related in the physical world. In the second place, A and B must be, and be known to be, real with the reality of a physical event, otherwise we could never come to apprehend them as related by way of succession in the physical world.