53-57.) In this way virtue becomes naturally a very good thing for
every one else but its possessor, but to him it is a natural evil,
inasmuch as it deprives him of pleasure, which natural evil by habit
is gradually converted into a factitious and artificial good, the man
becoming accustomed to it, as the proverb says, "like eels to
skinning." This theory is the resuscitation of one current among the
Sophists at Athens, and described by Plato thus.--The natural good of
man is to afford himself every indulgence, even at the expense of his
neighbours. He follows his natural good accordingly: so do his
neighbours follow theirs, and try to gratify themselves at his
expense. Fights ensue, till mankind, worried and wearied with
fighting, make a compact, each to give up so much of his natural good
as interferes with that of his neighbour. Human society, formed on
this understanding, enforces the compact in the interest of society.
Thus the interest of society is opposed to the interest of the
individual, in this that it keeps him out of his best natural good,
which is to do as his appetite of pleasure bids him in all things,
though it compensates him with a second-class good, by preventing his
neighbours from pleasure-hunting at his expense. If then his
neighbours could be restrained, and he left free to gratify himself,
that would be perfect bliss. But only a despot here or there has
attained to it. The ordinary man must pay his tax of virtue to the
community, a loss to him, but a gain to all the rest: while he is
compensated by the losses which their virtue entails upon them.

Such was the old Athenian theory, which John Mill, the Principle of
Utility in his hand, completes by saying that by-and-bye, and little
by little (as the prisoner of Chillon came to love his dungeon), the
hampered individual comes to love, and to find an artificial happiness
in, those restrictions of his liberty, which are called Virtue.