Adelard of Bath (lived 12th century)

English philosopher and student of mathematics and science. He translated Euclid's Stoicheia/Elements from Arabic into Latin and wrote De Eodem et Diverso/On Identity and Difference (1113–33), which establishes him as the founder of the doctrine of indifference, according to which the reality of universals is reconciled with that of individuals. This attempt at reconciliation distinguished him from other Platonists.

One of the most versatile men of his age, he was distinguished in many fields, including philosophy, theology, natural sciences, and mathematics. One of the best known of his published works is Quaestiones naturales/Natural Questions c. 1130, in which he uses Aristotle's argument from motion to establish the existence of God.