The irreversible is an expression of the fact that man cannot return to the past, nor can the past return as past. The irrevocable signifies that "having been" -- mainly, "having done" -- cannot be annihilated: what has been done cannot be undone. . . .
Remorse opposes its specifically ethical character to the aestheticizing and intensely felt character of regret. It is no less poignant for this. . . .
[O]ne must not count upon temporal erosion to revoke the past but upon the act that unbinds. One must then keep in mind the idea that "revocation leaves behind it an irreducible residue."