This article reconstructs some of the most influential Buddhist arguments in defense of idealism. It begins by clarifying the central theses under dispute and rationally reconstructs arguments from four major Buddhist figures in defense of some or all of these theses. It engages arguments from Vasubandhu’s Viṃśikā and Triṃśikā; Dignāga’s matching-failure argument in the Ālambanaparīkṣā; the sahopalambhaniyama inference developed by Dharmakīrti; and Xuanzang’s weird but clever logical argument that intrigued philosophers in China and Japan. It aims to clarify what is being argued and motivate these arguments in terms of their presuppositions. These presuppositions range from views about the nature of mind and metaphysics to epistemology and logic. By making this context explicit, this article introduces central ideas in Buddhist philosophy and suggests ways in which they were mobilized in support of an idealist conclusion.