Medieval philosophy was the historical period of thought from the fourth through the fourteenth centuries, which was dominated by religious concerns, the study of ancient Greek philosophy, and a need to reconcile rational inquiry with religious faith. It was mainly, but not completely, limited to the implications of Christian doctrine. Thus, St. Augustine (354–430) in the fourth century gave Christianity its first philosophical foundation in politics and ethics; and at the end of the era Nicolas of Oresme (1323–1382), in working out Aristotelian theories of motion that were approved by the Church, he was able to anticipate infinitesimal calculus and coordinate geometry, before Galileo’s mechanical theories.