This article explores the epistemological ramifications of understanding Thomas Aquinas’ conception of truth in terms of a dynamic process of cognitive assimilation within the human psyche. In particular, the author addresses two potential pitfalls for his theory, namely ‘failed assimilation’ as the basis of false judgments and ‘negative assimilation’, i.e., correspondence to non-being: how is the human mind capable of assimilation to ‘nothing’ at all? Aquinas addresses these two problems in various passages throughout his works; the author connects and reviews (...) their arguments with regard to their philosophical cogency and attempts to answer the question of whether Aquinas ultimately succeeds in solving the several puzzles that ‘failed’ as well as ‘negative assimilation’ seem to create in his conception of truth. (shrink)