Therefore Aristotle’s statement in the Posterior Analytics that “since the object of pure scientific knowledge cannot be other than it is, the truth obtained by demonstrative knowledge will be necessary” (1.3 73a2–23), was epistemologically insufficient for Sanches. Such necessity would merely be the syllogistic necessity of a conclusion following from arbitrary premises. But beyond the logical, there was also a psychological dimension to Sanches’ scepticism, which is implicit in the rhetorical