From 1772 or so, some haunting words of Diderot’s that spring up almost from nowhere in the middle of his thoughts on physiology, including a grim paraphrase of Cicero’s old maxim:
I shall not know until the end what I have lost or gained in this vast gaming-house, where I shall have passed some threescore years, dice-box in hand, tesseras agitans.
What do I perceive? Forms. And what besides? Forms. Of the substance I know nothing. We walk among shadows, ourselves shadows to ourselves and to others.
If I look at a rainbow traced on a cloud, I can perceive it; for him who looks at it from another angle, there is nothing.
A fancy common enough among the living is to dream that they are dead, that they stand by the side of their own corpse, and follow their own funeral. It is like a swimmer watching his garments stretched out on the shore.
Philosophy, that habitual and profound meditation which takes us away from all that surrounds us, which annihilates our own personality, is another apprenticeship for death.