  Sylvan is known for proposing and defending some highly controversial views, arguing in favour of inconsistent theories, non-existent objects, and non-human values. Such unorthodox claims were especially unpopular in the time Sylvan was writing, in the latter half of the 20th century. But he thought it was vitally important, for philosophy and for the world, that we take seriously ideas that run against conventions of the time. (As Robert Meyer put it, “To get the counter-suggestible Sylvan to defend some view, one needed first to remark that the view was now utterly discredited”, Meyer 1996.) What were widely thought to be untenable positions, such as Meinongianism, or failed theories, such as Cantor/Frege naïve set theory, attracted Sylvan’s attention for what he thought of as restoration: