But the ancients were quite as familiar with the same truth under other
images. "The cask," wrote Horace, "will long retain the odour of that
which has once been poured into it when new." Quintilian, describing the
depraved influences which surrounded even the infancy of a Roman child,
said, "From these arise _first familiarity, then nature_."

No one has laid down the principle more emphatically than Seneca
himself. Take, for instance, the following passage from his Letters, on
evil conversation. "The conversation," he says, "of these men is very
injurious; for, even if it does no immediate harm, it leaves its seeds
in the mind, and follows us even when we have gone from the speakers,--a
plague sure to spring up in future resurrection. Just as those who have
heard a symphony carry in their ears the tune and sweetness of the song
which entangles their thoughts, and does not suffer them to give their
whole energy to serious matters; so the conversation of flatterers and
of those who praise evil things, lingers longer in the mind than the
time of hearing it. Nor is it easy to shake out of the soul a sweet
sound; it pursues us, and lingers with us, and at perpetual intervals
recurs. Our ears therefore must be closed to evil words, and that to the
very first we hear. For when they have once begun and been admitted,
they acquire more and more audacity;" and so he adds a little
afterwards, "our days flow on, and irreparable life passes beyond our
reach." Yet he who wrote these noble words was not only a flatterer to
his imperial pupil, but is charged with having deliberately encouraged
him in a foolish passion for a freedwoman named Acte, into which Nero
fell. It was of course his duty to recall the wavering affections of the
youthful Emperor to his betrothed Octavia, the daughter of Claudius, to
whom he had been bound by every tie of honour and affection, and his
union with whom gave some shadow of greater legitimacy to his practical
usurpation. But princes rarely love the wives to whom they owe any part
of their elevation. Henry VII. treated Elizabeth of York with many
slights. The union of William III. with Mary was overshadowed by her
superior claim to the royal power; and Nero from the first regarded with
aversion, which ended in assassination, the poor young orphan girl who
recalled to the popular memory his slender pretensions to hereditary
empire, and whom he regarded as a possible rival, if her cowed and
plastic nat