Letters 50.7

There is nothing, Lucilius, to hinder you from entertaining good hopes about us, just because we are even now in the grip of evil, or because we have long been possessed thereby. There is no man to whom a good mind comes before an evil one. It is the evil mind that gets first hold on all of us. Learning virtue means unlearning vice.

Seneca, Letters to Lucilius 50.7, translated by Richard Mott Gummere