Letters 94.31

“But suppose,” people retort, “that a man is not the possessor of sound dogmas, how can advice help him when he is chained down by vicious dogmas?” In this, assuredly, that he is freed therefrom; for his natural disposition has not been crushed, but over-shadowed and kept down. Even so it goes on endeavouring to rise again, struggling against the influences that make for evil; but when it wins support and receives the aid of precepts, it grows stronger, provided only that the chronic trouble has not corrupted or annihilated the natural man. For in such a case, not even the training that comes from philosophy, striving with all its might, will make restoration. What difference, indeed,—is there between the dogmas of philosophy and precepts, unless it be this—that the former are general and the latter special? Both deal with advice—the one through the universal, the other through the particular.

Seneca, Letters to Lucilius 94.31, translated by Richard Mott Gummere