  The metaphysical version presented by Thomas Aquinas is the best known: “Veritas est adaequatio rei et intellectus” (Truth is the equation of thing and intellect), which he restates as: “A judgment is said to be true when it conforms to the external reality”. He tends to use “conformitas” and “adaequatio”, but also uses “correspondentia”, giving the latter a more generic sense (De Veritate, Q.1, A.1-3; cf. Summa Theologiae, Q.16). Aquinas credits the Neoplatonist Isaac Israeli with this definition, but there is no such definition in Isaac. Correspondence formulations can be traced back to the Academic skeptic Carneades, 2nd century B.C., whom Sextus Empiricus (Adversos Mathematicos, vii, 168) reports as having taught that a presentation “is true when it is in accord (symphonos) with the object presented, and false when it is in discord with it”. Similar accounts can be found in various early commentators on Plato and Aristotle (cf. Künne 2003, chap. 3.1), including some Neoplatonists: Proklos (In Tim., II 287, 1) speaks of truth as the agreement or adjustment (epharmoge) between knower and the known. Philoponus (In Cat., 81, 25-34) emphasizes that truth is neither in the things or states of affairs (pragmata) themselves, nor in the statement itself, but lies in the agreement between the two. He gives the simile of the fitting shoe, the fit consisting in a relation between shoe and foot, not to be found in either one by itself. Note that his emphasis on the relation as opposed to its relata is laudable but potentially misleading, because x’s truth (its being true) is not to be identified with a relation, R, between x and y, but with a general relational property of x, taking the form (∃y)(xRy &amp; Fy). Further early correspondence formulations can be found in Avicenna (Metaphysica, 1.8-9) and Averroes (Tahafut, 103, 302). They were introduced to the scholastics by William of Auxerre, who may have been the intended recipient of Aquinas’ mistaken attribution (cf. Boehner 1958; Wolenski 1994).