"His aversion to religion, in the sense usually attached to the term, was of the same kind with that of Lucretius: he regarded it with the feelings due not to a mere mental delusion, but to a great moral evil. He looked upo it as the greatest enemy of morality: first, by setting up factitious excellencies - belief in creeds, devotional feelings, and ceremonies, not connected with the good of human kind - and causing these to be accepted as substitutes for genuine virtue: but above all, by radically vitiating the standard of morals; making it consist in doing the will of a being, on whom it lavishes indeed all the phrases of adulation, but whom in sober truth it depicts as eminently hateful."
~ John Stuart Mill on his father, in the Autobiography
"Tantum religio potuit suadere malorum."
("To such heights of evil are men driven by religion.")
~ Lucretius, De Rerum Natura