travel for the sake of going about; so in all cases there is a
tendency to elevate into an end that which was, to start with, only
valued as a means to an end. So the means of happiness, by being
habitually pursued, come to be a part of happiness. Habit is a second
nature, and we indulge a habit as we gratify nature. This tendency
works itself to an evil extreme in cases where men are become the
slaves of habit, and do a thing because they are got into the way of
doing it, though they allow that it is a sad and sorry way, and leads
them wide of true happiness. These instances show perversion of the
normal operation of the will.

_Readings_.--St. Thos., 1a 2a, q. 1, art. 4, in corp.; _ib_., q. 1,
art. 6, 7; _ib_., q. 5, art. 8; Ar., _Eth_., I., vii., 4, 5.


SECTION II.--_Definition of Happiness_.


1. Though all men do all things, in the last resort, that it may be
well with them and theirs, that is, for happiness vaguely apprehended,
yet when they come to specify what happiness is, answers so various
are given and acted upon, that we might be tempted to conclude that
each man is the measure of his own happiness, and that no standard of
happiness for all can be defined. But it is not so. Man is not the
measure of his own happiness, any more than of his own health. The
diet that he takes to be healthy, may prove his poison; and where he
looks for happiness, he may find the extreme of wretchedness and woe.
For man must live up to his nature, to his bodily constitution, to be
a healthy man; and to his whole nature, but especially to his mental
and moral constitution, if he is to be a happy man. And nature, though