[A] I had already written my Critique of Sigwart’s notion of existence when I became aware of a note in his _Logic_, second ed, p. 390, a passage which, while it has not made it necessary to alter anything which I had written, has led me to insert it for the purpose of comparison. “Das Seiende überhaupt,” Sigwart writes, “kann nicht als wahrer Gattungsbegriff zu dem einzelnen Seienden betrachtet werden; es ist, begrifflich betrachtet, nur ein gemeinschaftlicher Name. Denn, da ‘Sein’ für uns ein Relationsprädikat ist, kann es kein gemeinschaftliches Merkmal sein, es müsste denn gezeigt werden, dass dieses Prädikat in einer dem Begriffe alles Seienden gemeinsamen Bestimmung wurzle.” I fear that the reader will, just as little as myself, attain by this explanation to clearness concerning Sigwart’s notion of existence. He will perhaps the better understand why all my efforts regarding it have proved futile. s Sigwart has failed to grasp the nature of judgment in general he is not, of course, able to understand that of the _negative_ judgment in particular. He has gone so far in error as to deny to it an equal right as species along with the positive judgment; no negative judgment is, he thinks, a direct judgment, its object is rather always another actual judgment or the attempt to form such a judgment.
In this assertion Sigwart is opposed to some important psychological views which I have made good in my lecture. It would therefore seem fitting to resist his attack. For this purpose I shall show: (1) that Sigwart’s doctrine is badly founded; (2) that it leads to an irremediable confusion, as in that case Sigwart’s affirmative judgment is a negative judgment, while his negative judgment if indeed a judgment at all, and not rather the absence of one, is a positive judgment, and that moreover his positive judgment really involves a negative one, along with other similar confusions. (3) Finally I think it will be possible--thanks to Sigwart’s detailed explanations--to show the genesis of his error.
1. The first inquiry in the case of an assertion so novel and so widely diverging from the general view, will be as to its foundation. With regard to this, he insists above all (p. 150) that the negative judgment would have no meaning if the thought of the positive attribution of a predicate had not preceded. But what can this mean? Either there is here a clear _petitio principii_, or it cannot mean anything more than that a connection of ideas must have preceded. Now granting this for a moment (although I have in my _Psychology_ shown its falsity) this would by no means prove his proposition, since Sigwart himself recognizes (p. 89 note, and elsewhere) that such a “subjective connexion of ideas” would still not be a judgment; that there needs rather to be added to it a certain feeling of constraint.