"The [secular] sense of right and wrong is so delicate, so fitful, so easily puzzled, obscured, perverted, so subtle in its argumentative methods, so impressionable by education, so biased by pride and passion, so unsteady in its course, that in the struggle for existence amid the various exercises and triumphs of the human intellect, the sense is at once the highest of all teachers yet the least luminous."
~ John Henry Newman, "Letter to the Duke of Norfolk", from the article on Morality by G. H. Joyce.