Page:On the Fourfold Root, and On the Will in Nature.djvu/53

 does not place the principle of sufficient reason in Logic, as is now the custom, but in Ontology. True, in § 71 he urges the necessity of not confounding the principle of sufficient reason of knowing with that of cause and effect ; still he does not clearly determine here wherein the difference consists. Indeed, he himself mistakes the one for the other ; for he quotes instances of cause and effect in confirmation of the principium rationis sufficientis in this very chapter, de ratione sufficiente, §§ 70, 74, 75, 77, which, had he really wished to preserve that distinction, ought rather to have been quoted in the chapter de causis of the same work. In said chapter he again brings forward precisely similar instances, and once more enunciates the principium cognoscendi (§ 876), which does not certainly belong to it, having been already discussed, yet which serves to introduce the immediately following clear and definite distinction between this principle and the law of causality, §§ 881-884. Principium, he continues, dicitur id, quod in se continet rationem alterius; and he distinguishes three kinds : 1. (causa), which he defines as ratio actualitatis alterius, e.g., si lapis calescit, ignis aut radii solares sunt rationes, cur calor lapidi insit.—2. , which he defines as ratio possibilitatis alterius; in eodem exemplo, ratio possibilitatis, cur lapis calorem recipere possit, est in essentia seu modo compositionis lapidis. This last conception seems to me inadmissible. If it has any meaning at all, possibility means correspondence with the general conditions of experience known to us à priori, as Kant has sufficiently shown. From these conditions we know, with respect to Wolf's instance of the stone, that changes are possible as effects proceeding from causes : we know, that is, that one state can succeed another, if the former contains the conditions for the latter. In this case we find, as effect, the state of being warm in the stone ; as cause, the preceding state of a limited capacity for