. Moreover, as
when we see a fitness within our sphere of action, we perceive intuitively
that it is right to respect it, wrong to violate it, our knowledge of
right and wrong is co-extensive with our knowledge of persons and things.
The more enlightened and cultivated a nation is, then, the more does it
know as to right and wrong, whatever may be its standard of practical
morality.

For instance, in the most savage condition, men know, with reference to
certain articles of *food and drink*, that they are adapted to relieve the
cravings of hunger and thirst, and they know nothing more about them. They
are not acquainted with the laws of health, whether of body or of mind.
They therefore eat and drink whatever comes to hand, without imagining the
possibility of wrong-doing in this matter. But, with the progress of
civilization, they learn that various kinds of food and drink impair the
health, cloud the brain, enfeeble the working power, and therefore are
unfit for human use; and no sooner is this known, than the distinction of
right and wrong begins to be recognized, as to what men eat and drink. The
more thorough is the knowledge of the human body and of the action of
various substances on its organs and tissues, the more minute and
discriminating will be the perception of fitness or unfitness as to the
objects that tempt the appetites, and the keener will be the sense of
right or wrong in their use.

For another illustration of the same principle, we may take *the relation
between parents and children*. In the ruder stages of society, and
especially among a nomadic or migratory people, there is not a sufficient
knowledge of the resources of nature or the possibilities of art, to
render even healthy and vigorous life more than tolerable; while for the
infirm and feeble, life is but a protracted burden and weariness. At the
same time, there is no apprehension of the intellectual and moral worth of
human life, still less, of the value even of its most painful experiences
as a discipline of everlasting benefit. In fine, life is little more than
a mere struggle for existence. What wonder then, that in some tribes
filial piety has been wont to relieve superannuated parents from an
existence devoid equally of joy and of hope; and that in others parental
love may have even dictated the exposure--with a view to their perishing--of
feeble, sickly, and deformed children, incapable of being nurtured into
self-sustaining and self