He took his M.D. at Edinburgh, his doctoral thesis of 1808 being his first attempt at the great question of his life: the origin of human varieties and races.[4] Later, he read for a year at Trinity College, Cambridge,[5] after which came a significant personal event: he left the Society of Friends to join the established Church of England. He next moved to St John's College, Oxford, afterwards entering as a gentleman commoner at Trinity College, Oxford, but taking no degree in either university.[3]