It is not the end of joy that makes old age so sad, but the end of hope.
In science the new is an advance; but in morals, as contradicting our inner ideals and historic idols, it is ever a retrogression.
Sleep, riches, and health, to be truly enjoyed, must be interrupted.
Nothing is more beautiful than cheerfulness in an old face.
If self-knowledge is the road to virtue, so is virtue still more the road to self-knowledge.
Never write on a subject without first having read yourself full on it; and never read on a subject till you have thought yourself hungry on it.