 Łukasiewicz described himself later as attempting in the monograph to devise a “non-Aristotelian logic” but admits that he did not succeed, principally because at this stage he was not prepared to reject the principle of bivalence. It may well be Meinong’s influence at work when Łukasiewicz comes to give his natural-language renderings of the symbolism of Couturat’s algebra of logic in the Appendix. There is little or no trace of the propositional logic that Łukasiewicz was to make very much his own: the renderings are clumsily object-theoretic: the constant ‘0’ for example, which might be naturally construed as a constant false proposition (and is so in later Łukasiewicz) is rendered as “the object that does not exist”. This is one reason why Łukasiewicz’s formal work in the Appendix to the 1910 work appears relatively archaic. While the variable letters like \(a, b\) etc. “signify affirmative statements” and their negations \(a', b'\) etc. “signify negative statements”, and in practice do work like propositional variables and their negations in modern propositional logic, Łukasiewicz’s renderings of them are curiously hybrid: ‘\(a\)’ is rendered as ‘\(X\) contains \(a\)’ and ‘\(a'\)’ as ‘\(X\) contains no \(a\)’, while ‘1’ signifies ‘\(X\) is an object’ and ‘0’ signifies ‘\(X\) is not an object’. This is all very confused, and by no means a classical sentential logic in intent, even if it works like one in practice.