Letters from a Stoic 95 : 14

Of course, as you say, the old-fashioned wisdom, especially in its beginnings, was crude; but so were the other arts, in which dexterity developed with progress. Nor indeed in those days was there yet any need for carefully-planned cures. Wickedness had not yet reached such a high point, or scattered itself so broadcast. Plain vices could be treated by plain cures; now, however, we need defences erected with all the greater care, because of the stronger powers by which we are attacked.