"The bitterest sorrow that man can know is to aspire to do much and to achieve nothing"… so Herodotus relates that a Persian said to a Theban at a banquet (book ix., chap. xvi.). And it is true. With knowledge and desire we can embrace everything, or almost everything; with the will nothing, or almost nothing. And contemplation is not happiness — no! not if this contemplation implies impotence. And out of this collision between our knowledge and our power pity arises.

The Tragic Sense of Life (1913) - VII : Love, Suffering, Pity