The refutation of _rational psychology_ is much fuller and more thorough in the first edition of the “Critique of Pure Reason” than in the second and following editions, and therefore upon this point we must make use of the first edition exclusively. This refutation has as a whole very great merit and much truth. Yet I am clearly of the opinion that it was merely from his love of symmetry that Kant deduced as necessary the conception of the soul from the paralogism of substantiality by applying the demand for the unconditioned to the conception _substance_, which is the first category of relation, and accordingly maintained that the conception of a soul arose in this way in every speculative reason. If this conception really had its origin in the presupposition of a final subject of all predicates of a thing, one would have assumed a soul not in men alone, but also just as necessarily 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,