Abstract

Thomas Aquinas was a scholastic theologian who was active in the thirteenth century when scholars of the Latin west were assimilating the nearly complete Aristotelian corpus (rendered into Latin by 1200). These writings transformed every field of philosophical enquiry, and reflected a worldview that led some medievals to assert that philosophical reasoning does not agree with revelation, on points including freedom of will, personal immortality, and God’s awareness of creation. Against this, Aquinas argued that valid reasoning cannot contradict articles of faith, as both flow from God. This famous synthesis of faith and reason helped to develop an intellectual culture that allowed for the development of Aristotelian empiricism alongside scholasticism’s deeply embedded Platonic elements. Yet Aquinas was no mere apologist. Just as he produced numerous excellent commentaries on Aristotle, Aquinas likewise developed a metaphysics asserting a distinction between being and essence with respect to all entities save God. Joining to this distinction the medieval doctrine of the convertibility of goodness, truth, and being (the transcendentals), Aquinas develops a Christian Aristotelianism that informs his natural theology, ethics, theory of natural law, philosophy of mind, and philosophy of language (treated in this entry). Aquinas’ proofs for God’s existence adduce the existence of contingent entities (for whom essence and existence are distinct) to demonstrate that of a necessary entity (for whom essence and existence are identical), viz., God. Through the aforementioned convertibility of the tran-scendentals, as maximally existent, God is maximally good. Carrying this over to philosophy of mind, ethics, and natural law theory, Aquinas explains our free actions in terms of an innate desire for happiness, the chief human good, which desire is, at bottom, a desire for the beatific vision in which the highest possible happiness is obtained. Aquinas’ philosophy of language then seeks to regulate the signification of theological discourse, bearing in mind God’s unique nature.