  The 5th and early to mid-4th centuries BCE also see great interest in fallacies and logical paradoxes. Besides the Liar, Eubulides is said to have been the originator of several other logical paradoxes, including the Sorites. Plato’s Euthydemus contains a large collection of contemporary fallacies. In attempts to solve such logical puzzles, a logical terminology develops here, too, and the focus on the difference between valid and invalid arguments sets the scene for the search for a criterion of valid inference. Finally, it is possible that the shaping of deduction and proof in Greek mathematics that begins in the later 5th century BCE served as an inspiration for Aristotle’s syllogistic.