This thinker anticipated Descartes’s exploration of the ability of God to deceive people by discussing the process by which intuitive and abstract cognitions lead to beliefs. This thinker built on Aristotle’s idea of a mental language to analyze concepts as “natural signs,” (15[1])developing an early version of the language of thought hypothesis. This philosopher reduced the number of categories in his ontology from ten down to two, (*) substance and quality. This philosopher argued that certain entities were merely the result of thinking of several particulars at once after abandoning his fictum-theory of them. John Duns Scotus’s realism about universals was disputed by this nominalist’s Summa of Logic. For 10 points, the idea that “entities should not be multiplied beyond necessity” is what medieval philosopher’s namesake razor? ■END■