Fuegians. So also a growing child is substantially egoistic, and it
must be taught by precept and example that the rights of others can be
safeguarded only by the altruistic correction of personal action, long
before the child can grasp the higher conceptions of ethics. If a human
being never learns to do so, and becomes a criminal through force of
heredity or circumstances, the machinery of the law automatically comes
into operation to conserve the welfare of the community. Such a criminal
may be unable to control his destiny, and may not be responsible for being
what he is, but nevertheless he must pay the penalty for his unsocial
heritage by suffering elimination.

Ethical systems are built around man's vague recognition of certain
natural obligations, and they have thus become more or less complex, and
more or less varied as worked out by different peoples. They must
necessarily be much concerned with social questions, with morals in the
usual sense and the more rigid principles enacted into the spoken and
printed law, but they have also become closely connected with religion and
theological elements. Especially is this true in the ethics of barbarous
and savage peoples, who accredit the "categorical imperative" to some
supernatural power, as we are to see in a later section. The one point
that comes out clearly is that the systems of conduct and duties have
evolved so as to be very different among various races, and that in the
history of any one people, ethics has passed through many varied
conditions. What may be deemed right at one period becomes wrong at
another when conditions may be changed; in medieval England the penalty of
death was prescribed for one who killed a king's deer, as well as for a
highway murderer. The Fijian of a quarter century ago killed his parents
when they became too old to be effective members of their tribe. And so
deeply ingrained was this principle of duty that elderly people would
voluntarily go to a living grave surrounded by their friends; while in
other authentic cases, parents have first killed their sons who failed to
obey the tribal law, and have then committed suicide. We can see how
nature and necessity would institute a law requiring such conduct where a
tribe must carry on almost incessant warfare and where the available food
supplies would be enough for only the most efficient individuals.
Infanticide also has been practised for reasons of biological utility, as
among the