Boethius's most recognized work was the Consolation Of Philosophy, which he wrote in prison in Pavia waiting to be executed. Boethius also translated some of Aristotle's works on logic from Greek into Latin, and until the 12th century they were the only significant portions of Aristotle available in that language.
Boethius also wrote a commentary on the Isagoge? by Porphyry?, in which he discusses the nature of the species: whether they are subsistent entities which would exist whether anyone thought of them, or whether they exist as ideas alone. This work started one of the most vocal controversies in [medieval philosophy]?. Taken more generally the question of the ontological? nature of universal ideas became known as the problem of universals.