A quote
Let us disagree with Epicurus on the one point, when he declares that there is no natural justice, and that crime should be avoided because one cannot escape the fear which results therefrom; let us agree with him on the other—that bad deeds are lashed by the whip of conscience, and that conscience is tortured to the greatest degree because unending anxiety drives and whips it on, and it cannot rely upon the guarantors of its own peace of mind. For this, Epicurus, is the very proof that we are by nature reluctant to commit crime, because even in circumstances of safety there is no one who does not feel fear.
Seneca·Letter 97 — On the Degeneracy of the Age (§15)·trans. Gummere