Almost anything that can be praised or advocated has been put to some disgusting use. There is no principle, however immaculate, that has not had its compromising manipulator. – Percy Wynham Lewis

Amid the pressure of great events, a general principle gives no help. – G. W. F. Hegel

The American doctrinaire is the converse of the American demagogue, and, in this way, is scarcely less injurious to the public. The first deals in poetry, the last in cant. He is as much a visionary on one side, as the extreme theoretical democrat is a visionary on the other. – James Fenimore Cooper

A striking feature of moral and political argument in the modern world is the extent to which it is innovators, radicals, and revolutionaries who revive old doctrines, while their conservative and reactionary opponents are the inventors of new ones. – Alasdair Chalmers Macintyre