I am beginning to feel that I am growing old; soon, I shall have to eat mush like children. I shall no longer be able to speak, which will be a rather great advantage for others and but a small inconvenience for myself.... The time in which I count in years is gone; that in which I count in days is here.... I had thought that the fibers of the heart would grow callous with age, it's not at all the case. I am not sure that my sensitivity hasn't increased; everything moves me, affects me.... To fade out between a man feeling your pulse and another bothering your head; not to know where one comes from, why one came, where one is going...

Letter to his sister Denise, as quoted in Diderot, Reason and Resonance (1982) by Élisabeth de Fontenay, pp. 270–271