in every lifeless thing, for such a thing also requires a final subject of all its predicates. Speaking generally, however, Kant makes use of a quite inadmissible expression when he talks of something which can exist only as subject and not as predicate (e. g., Critique of Pure Reason, p. 323; V. 412; Prolegomena, § 4 and 47); though a precedent for this is to be found in Aristotle's “Metaphysics,” iv. ch. 8. Nothing whatever exists as subject and predicate, for these expressions belong exclusively to logic, and denote the relations of abstract conceptions to each other. Now their correlative or representative in the world of perception must be substance and accident. But then we need not look further for that which exists always as substance and never as accident, but have it directly in matter. It is the substance corresponding to all properties of things which are their accidents. It is, in fact, if one wishes to retain the expression of Kant which has just been condemned, the final subject of all predicates of that empirically given thing, that which remains after the abstraction of all its properties of every kind. And this holds good of man as of a brute, a plant, or a stone, and is so evident, that in order not to see it a determined desire not to see is required. That it is really the prototype of the conception substance, I will show soon. But subject and predicate are related to substance and accident rather as the principle of sufficient reason in logic to the law of causality in nature, and the substitution or identification of the former is just as inadmissible as that of the latter. Yet in the “Prolegomena,” § 46, Kant carries this substitution and identification to its fullest extent in order to make the conception of the soul arise from that of the final subject of all predicates and from the form of the categorical syllogism. In order to discover the sophistical nature of this paragraph, one only needs to reflect that subject and predicate are purely logical determinations, which concern abstract conceptions solely and alone, and that according to their relation in the judgment. Substance and accident, on the other hand, belong to the world of perception and its apprehension in the understanding, and are even there only as identical with matter and form or quality. Of this more shortly.
The antithesis which has given occasion for the assumption of two fundamentally different substances, body and soul, is in truth that of objective and subjective. If a man apprehends himself objectively in external perception, he finds a being extended in space and in general merely corporeal; but if, on the other hand, he apprehends himself in mere self-consciousness, thus purely subjectively, he finds himself a merely willing and perceiving being, free from all forms of perception, thus also without a single one of the properties which belong to bodies. Now he forms the conception of the soul, like all the transcendental conceptions called by Kant Ideas, by applying the principle of sufficient reason, the form of all objects, to that which is not an object, and in this case indeed to the subject of knowing and willing. He treats, in fact, knowing, thinking, and willing as effects of which he seeks the cause, and as he cannot accept the body as their cause, he assumes a cause of them entirely different from the body. In this manner the first and the last of the dogmatists proves the existence of the soul: Plato in the “Phædrus” and also Wolf: from thinking and willing as the effects which lead to that cause. Only after in this way, by hypostatising a cause corresponding to the effect, the conception of an immaterial, simple, indestructible being had arisen, the school developed and demonstrated this from the conception of substance. But this conception itself they had previously constructed specially for this purpose by the following artifice, which is worthy of notice.
With the first class of ideas, i. e., the real world of perception, the idea of matter is also given; because the law governing this class of ideas, the law of causality, determines the change of the states or conditions, and these conditions themselves presuppose something permanent, whose changes they are. When speaking above of the principle of the permanence of substance, I showed, by reference to earlier passages, that this idea of matter arises because in the understanding, for which alone it exists, time and space are intimately united, and the share of space in this product exhibits itself as the permanence of matter, while the share of time appears as the change of states. Purely in itself, matter can only be thought in abstracto, and not perceived; for to perception it always appears already in form and quality. From this conception of matter, substance is again an abstraction, consequently a higher genus, and arose in this way. Of the conception of matter, only the predicate of permanence was allowed to remain, while all its other essential properties, extension, impenetrability, divisibility, &c., were thought away. Like every higher genus, then, the concept substance contains less in itself than the concept matter, but, unlike every other higher genus, it does not contain more under it, because it does not include several lower genera besides matter; but this remains the one true species of the concept substance, the only assignable thing by which its content is realised and receives a proof. Thus the aim with which in other cases the reason produces by abstraction a higher conception, in order that in it several subordinate species may be thought at once through common determinations, has here no place; consequently that abstraction is either undertaken idly and entirely without aim, or it has a secret secondary purpose. This secret purpose is now brought to light; for under the conception substance, along with its true sub-species matter, a second species is co-ordinated – the immaterial, simple, indestructible substance, soul. But the surreptitious introduction of this last concept arose from the fact that the higher concept substance was framed illogically, and in a manner contrary to law. In its legitimate procedure the reason always frames the concept of a higher genus by placing together the concepts of several species, and now comparing them, proceeds discursively, and by omitting their differences and retaining the qualities in which they agree, obtains the generic concept which includes them all but has a smaller content. From this it follows that the concepts of the species must always precede the concept of the genus. But, in the present case, the converse is true. Only the concept matter existed before the generic concept substance. The latter was without occasion, and consequently without justification, as it were aimlessly framed from the former by the arbitrary omission of all its determinations except one. Not till afterwards was the second ungenuine species placed beside the concept matter, and so foisted in. But for the framing of this second concept nothing more was now required than an express denial of what had already been tacitly omitted in the higher generic concept, extension, impenetrability, and divisibility. Thus the concept substance was framed merely to be the vehicle for the surreptitious introduction of the concept of the immaterial substance. Consequently, it is very far from being capable of holding good as a category or necessary function of the understanding; rather is it an exceedingly superfluous concept, because its only true content lies already in the concept of matter, besides which it contains only a great void, which can be filled up by nothing but the illicitly introduced species immaterial substance; and, indeed, it was solely for the purpose of containing this that it was framed. Accordingly, in strictness, the concept substance must be entirely rejected, and the concept matter everywhere put in its place.
The categories were a procrustean bed for every possible thing, but the three kinds of syllogisms are so only for the three so-called Ideas. The Idea of the soul was compelled to find its origin in the form of the categorical syllogism. It is now the turn of the dogmatic ideas concerning the universe, so far as it is thought as an object in itself, between two limits – that of the smallest (atom), and that of the largest (limits of the universe in time and space). These must now proceed from the form of the hypothetical syllogism. Nor for this in itself is any special violence necessary. For the hypothetical judgment has its form from the principle of sufficient reason, and not the cosmological alone but all those so-called Ideas really have their origin in the inconsiderate and unrestricted application of that principle, and the laying aside of it at pleasure. For, in accordance with that principle, the mere dependence of an object upon another is ever sought for, till finally the exhaustion of the imagination puts an end to the journey; and thus it is lost sight of that every object, and indeed the whole chain of objects and the principle of sufficient reason itself, stand in a far closer and greater dependence, the dependence upon the knowing subject, for whose objects alone, i. e., ideas, that principle is valid, for their mere position in space and time is determined by it. Thus, since the form of knowledge from which here merely the cosmological Ideas are derived, the principle of sufficient reason, is the source of all subtle hypostases, in this case no sophisms need be resorted to; but so much
