The period known as scholasticism dominated the eleventh to thirteenth centuries. Two fundamental problems persisted for the better part of a millennium, from 529 to 1453. The first was the problem of universals. Briefly put, the problem was whether ideas like “triangle” and “purple” could exist apart from actual triangles and purple things, or whether they had no existence apart from things themselves. The second problem was devising logical proofs for the existence of God. The significant philosophers of the period addressed one or both of these problems.