To the man or woman who, by compulsion, is more civilized in behaviour than in feeling, rationality is irksome and virtue is felt as a burden and a slavery.
 Bertrand Russell, A History of Western Philosophy (1945). copy citation

Context

“Like all communities that have been civilized quickly, the Greeks, or at least a certain proportion of them, developed a love of the primitive, and a hankering after a more instinctive and passionate way of life than that sanctioned by current morals. To the man or woman who, by compulsion, is more civilized in behaviour than in feeling, rationality is irksome and virtue is felt as a burden and a slavery. This leads to a reaction in thought, in feeling, and in conduct. It is the reaction in thought that will specially concern us, but something must first be said about the reaction in feeling and conduct.” source