Edward Gibbon contemplates the sad tale of the Roman emperor and Stoic philosopher, Marcus Aurelius, whose virtue and wisdom failed to produce either wisdom or virtue in his son and successor, Commodus:
The monstrous vices of the son have cast a shade on the purity of the father’s virtues. It has been objected to Marcus, that he sacrificed the happiness of millions to a fond partiality for a worthless boy; and that he chose a successor in his own family, rather than in the republic. Nothing however, was neglected by the anxious father, and by the men of virtue and learning whom he summoned to his assistance, to expand the narrow mind of young Commodus, to correct his growing vices, and to render him worthy of the throne for which he was designed. But the power of instruction is seldom of much efficacy, except in those happy dispositions where it is almost superfluous. —History of the Decline and Fall of the Roman Empire, Chapter IV
Marcus had perhaps not read, or simply did not heed, the words of Socrates in Plato’s Meno: “If through all this discussion our queries and statements have been correct, virtue is found to be neither natural nor taught, but is imparted to us as a divine gift without understanding in those who receive it” (tr. W. R. M. Lamb).