This thinker's propositional attitude puzzle concerns when substitutivity fails in sentences about (*) belief.
In one work, this thinker defined the natural numbers with the "ancestral relation," and in the preface to that work, this thinker noted that Leibniz underestimated the difficulties posed by creating a calculus philosophicus. Michael Dummett, who is well known for work about this philosopher, claims Wittgenstein's reference to him in the Tractatus explains why he is read today. This thinker's propositional attitude puzzle concerns when substitutivity fails in sentences about (*) belief. Bertrand Russell shows the deficiencies of the theories of Alexius Meinong and this thinker in "On Denoting." His identity puzzle refers to the fact that A equals A is a priori while A equals B is a posteriori, a fact that he illustrated with the morning star and the evening star. For 10 points, name this German philosopher who wrote Concept Script and "On Sense and Reference."
In one work, this thinker defined the natural numbers with the "ancestral relation," and in the preface to that work, this thinker noted that Leibniz underestimated the difficulties posed by creating a calculus philosophicus.
Gottlob Frege