Page:Mind (New Series) Volume 15.djvu/215

 KANT'S ANTITHESIS OF DOGMATISM AND CRITICISM. 201 taken in the strictest sense, is precisely the science which shows how knowledge a priori is to be had (scientia cognoscendi a priori). Now "whatever is known a priori is known ex internis veritatis characteribm " ; by this is meant, in modern^ language, that the presence of a priori knowledge is to be verified essentially by & psychological fact, namely, the actual inability of the mind to divorce certain predicates from one another. There are two kinds of universal judgment, and, only two, which are characterised by this inward compulsive- ness or necessity. Whereas in all other judgments predication is justified only a posteriori, since the subject is, as such, found to be thinkable as a single coherent notion without the im- plication of the given predicate in these two cases predication is necessary, and therefore valid universally and a priori, for the reason that the denial of the predicate carries with it for the mind the disappearance of the subject as a consistently definable and thinkable notion. 1 These two sorts of judgment a priori are distinguished from one another with respect to the manner in which the inseparability of predicate from subject is grounded. The first class is that of identical pro--] positions, in which the predicate is merely the whole (essentia) or a part (essentiale) of the attributes included in the defini-Ji tion of the subject. Such propositions are, evidently enough, axiomatic, that is to say, necessary yet indemonstrable truths ; but they are purely tautological and add nothing to our know- ledge. The second class of axioms is the one which is made possible by the existence of notiones fcecundce, and yields us, therefore, pregnant and instructive truths. Its logical char- acter consists in this, that the predicate in such proposi- tions is a " property " (attributum, Eigenschaft) of the subject. Whereas in the merely identical proposition, or definition, the several predicates are merely put together by the mind to make the chosen meaning, and do not co-determine the presence of one another, two "properties," on the other hand, stick together as inseparable "joint-determinations" of any subject into the definition of which either of them is introduced even though the framer of the definition may have meant to admit only one of them into his proposed meaning. 2 The test of a "property," once more, lies in the 1 " Notte entis aunt vel necessarise et immutabiles, quibus sublatis tolle- retur ^ns ; vel contingentes et mutabiles, quae possunt adesae et abesse salvo ente. Ad priores essentia. essentialia et attributa pertinent." From A croasis Loyica in Toellner's edition (1773), 171. The preceding citations are from other sections of the same. 2 Wolff, Philosophia rationalis sive Logica, 1728, 64, 65 : " Ea quse constanter enti cuidam insunt, quorum tarnen unurn per alterum non determinatur essentialia appello. . . . Ea quse constanter insunt, sed per essentialia simul determinantur, attributa dico."