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. ch. 8). 14. _Laws of Thought_, §118. 15. "Haud scio magis ne doctrinam modalium scholastici exercuerint, quam ea illos vexarit. Certe usque adeo sudatum hic fuit, ut dicterio locus sit datus; _De modalibus non gustabit asinus_." Keckermann, _Syst. Log._ Bk. II. ch. 3. 16. _Smiglecii Disputationes_, Ingolstadt, 1618. See also Prantl's _Geschichte der Logik_ (under _Occam_ and _Buridan_) for accounts of the excessive complication which the subtlety of those learned schoolmen evolved out of such suitable materials. 17. Translation by T. M. Lindsay, p. 439. 18. "The εἰκòς and σημεῖον themselves are propositions; the former stating a _general probability_, the latter a fact, which is known to be an indication, more or less certain, of the truth of some further statement, whether of a single fact, or of a general belief. The former is a general proposition, nearly, though not quite, universal; as 'most men who envy hate'; the latter is a _singular_ proposition, which however is not regarded as a sign, except relatively to some other proposition, which it is supposed may by inferred from it." (Mansel's Aldrich; Appendix F, where an account will be found of the Aristotelian enthymeme, and dialectic syllogism. Also, of course, Grote's Aristotle, _Topics_ and elsewhere.) 19. "Nam in hoc etiam differt demonstratio, sen demonstrativa argumentatio, à probabili, quia in illâ tam conclusio quam præmissæ necessariæ sunt; in probabili autem argumentatione sicut conclusio ut probabilis infertur ita præmissæ ut probabiles afferuntur" (Crackanthorpe, Bk. V., Ch. 1); almost the words with which De Morgan distinguishes between logic and probability in a passage already cited (see Ch. VI. §3).