judgment; for they are only applied to already completed judgments, in which the combination of the concepts remains unchanged the categorical. But they again connect these judgments, for the hypothetical form expresses their dependence upon each other, and the disjunctive their incompatibility. Mere concepts, however, have only one class of relations to each other, those which are expressed in the categorical judgment. The fuller determination, or the sub-species of this relation, are the intersection and the complete separateness of the concept-spheres, i. e., thus affirmation and negation; out of which Kant has made special categories, under quite a different title, that of quality. Intersection and separateness have again sub-species, according as the spheres lie within each other entirely, or only in part, a determination which constitutes the quantity of the judgments; out of which Kant has again made a quite special class of categories. Thus he separates what is very closely related, and even identical, the easily surveyed modifications of the one possible relation of mere concepts to each other, and, on the other hand, unites what is very different under this title of relation.
Categorical judgments have as their metalogical principle the laws of thought of identity and contradiction. But the ground of the connection of the concept-spheres which gives truth to the judgment, which is nothing but this connection, may be of very different kinds; and, according to this, the truth of the judgment is either logical, or empirical, or metaphysical, or metalogical, as is explained in the introductory essay, § 30-33, and does not require to be repeated here. But it is apparent from this how very various the direct cognitions may be, all of which exhibit themselves in the abstract, through the combination of the spheres of two concepts, as subject and predicate, and that we can by no means set up the sole function of the understanding as corresponding to them and producing them. For example, the judgments, “Water boils, the sine measures the angle, the will resolves, business distracts, distinction is difficult,” express through the same logical form the most different kinds of relations; but from this we obtain the right, however irregular the beginning may be, of placing ourselves at the standpoint of abstract knowledge to analyse direct intuitive knowledge. For the rest, the categorical judgment springs from knowledge of the understanding proper, in my sense, only when causation is expressed by it; this is, however, the case in all judgments which refer to a physical quality. For if I say, “This body is heavy, hard, fluid, green, sour, alkaline, organic, &c., &c.,” this always refers to its effect, and thus is knowledge which is only possible through the pure understanding. Now, after this, like much which is quite different from it (for example, the subordination of very abstract concepts), has been expressed in the abstract through subject and predicate, these mere relations of concepts have been transferred back to knowledge of perception, and it has been supposed that the subject and predicate of the judgment must have a peculiar and special correlative in perception, substance and accident. But I shall show clearly further on that the conception substance has no other true content than that of the conception matter. Accidents, however, are quite synonymous with kinds of effects, so that the supposed knowledge of substance and accident is never anything more than the knowledge of cause and effect by the understanding. But the special manner in which the idea of matter arises is explained partly in § 4 of the first book, and still more clearly in the essay on the principle of sufficient reason at the end of § 21, p. 77 (3d ed., p. 82), and in some respects we shall see it still more closely when we investigate the principle of the permanence of substance.
(c.) Disjunctive judgments spring from the law of thought of excluded third, which is a metalogical truth; they are, therefore, entirely the property of the reason, and have not their origin in the understanding. The deduction of the category of community or reciprocity from them is, however, a glaring example of the violence which Kant sometimes allowed to be done to truth, merely in order to satisfy his love of architectonic symmetry. The illegitimacy of that deduction has already often been justly condemned and proved upon various grounds, especially by G. E. Schulze in his “Kritik der theoretischen Philosophie,” and by Berg in his “Epikritik der Philosophie.” What real analogy is there, indeed, between the problematical determination of a concept by disjunctive predicates and the thought of reciprocity? The two are indeed absolutely opposed, for in the disjunctive judgment the actual affirmation of one of the two alternative propositions is also necessarily the negation of the other; if, on the other hand, we think two things in the relation of reciprocity, the affirmation of one is also necessarily the affirmation of the other, and vice versa. Therefore, unquestionably, the real logical analogue of reciprocity is the vicious circle, for in it, as nominally in the case of reciprocity, what is proved is also the proof, and conversely. And just as logic rejects the vicious circle, so the conception of reciprocity ought to be banished from metaphysics. For I now intend, quite seriously, to prove that there is no reciprocity in the strict sense, and this conception, which people are so fond of using, just on account of the indefiniteness of the thought, is seen, if more closely considered, to be empty, false, and invalid. First of all, the reader must call to mind what causality really is, and to assist my exposition, see upon this subject § 20 of the introductory essay, also my prize-essay on the freedom of the will, chap. iii. p. 27 seq., and lastly the fourth chapter of the second book of this work. Causality is the law according to which the conditions or states of matter which appear determine their position in time. Causality has to do merely with conditions or states, indeed, properly, only with changes, and neither with matter as such, nor with permanence without change. Matter, as such, does not come under the law of causality, for it neither comes into being nor passes away; thus neither does the whole thing, as we commonly express ourselves, come under this law, but only the conditions or states of matter. Further, the law of causality has nothing to do with permanence, for where nothing changes there is no producing of effects and no causality, but a continuing quiet condition or state. But if, now, such a state is changed, then the new state is either again permanent or it is not, but immediately introduces a third state, and the necessity with which this happens is just the law of causality, which is a form of the principle of sufficient reason, and therefore cannot be further explained, because the principle of sufficient reason is the principle of all explanation and of all necessity. From this it is clear that cause and effect stand in intimate connection with, and necessary relation to, the course of time. Only because the state A. precedes in time the state B., and their succession is necessary and not accidental, i. e., no mere sequence but a consequence – only because of this is the state A. cause and the state B. effect. The conception reciprocity, however, contains this, that both are cause and both are effect of each other; but this really amounts to saying that each of the two is the earlier and also the later; thus it is an absurdity. For that both states are simultaneous, and indeed necessarily simultaneous, cannot be admitted, because, as necessarily belonging to each other and existing at the same time, they constitute only one state. For the permanence of this state there is certainly required the continued existence of all its determinations, but we are then no longer concerned with change and causality, but with duration and rest, and nothing further is said than that if one determination of the whole state be changed, the new state which then appears cannot continue, but becomes the cause of the change of all the other determinations of the first state, so that a new third state appears; which all happens merely in accordance with the simple law of causality, and does not establish a new law, that of reciprocity.
I also definitely assert that the conception reciprocity cannot be supported by a single example. Everything that one seeks to pass off as such is either a state of rest, to which the conception of causality, which has only significance with reference to changes, finds no application at all, or else it is an alternating succession of states of the same name which condition each other, for the explanation of which simple causality is quite sufficient. An example of the first class is afforded by a pair of scales brought to rest by equal weights. Here there is no effect produced, for there is no change; it is a state of rest; gravity acts, equally divided, as in every body which is supported at its centre of gravity, but it cannot show its force by any effect. That the taking away of one weight produces a second state, which at once becomes the cause of the third, the sinking of the other scale, happens according to the simple law of cause and effect, and requires no special category of the understanding, and not even a special name. An example of the second class is
