[9] It may be remarked that Whately (Logic, Bk. II.
ch. II.
§ 2) speaks of necessary, impossible and contingent matter, without any apparent suspicion that they belong entirely to an obsolete point of view.
[10] Formal Logic, p. 233.
[11] The subject was sometimes altogether omitted, as by Wolf. He says a good deal however about probable propositions and syllogisms, and, like Leibnitz before him, looked forward to a “logica probabilium” as something new and desirable. I imagine that he had been influenced by the writers on Chances, as of the few who had already treated that subject nearly all the most important are referred to in one passage (Philosophia Rationalis sive Logica, § 593).
Lambert stands quite apart. In this respect, as in most others where mathematical conceptions and symbols are involved, his logical attitude is thoroughly unconventional. See, for instance, his chapter ‘Von dem Wahrscheinlichen’, in his Neues Organon.
[12] I cannot find the slightest authority for the statement in the elaborate history of Logic by Prantl.
[13] “Hi quatuor modi magnam censeri solent analogiam habere cum quadruplici propositionum in quantitate et qualitate varietate” (Wallis's Instit.
Logic.
Bk. II.