advanced nations have adopted compulsory monogamy, thereby giving the
prestige of their authority in favour of that system. But it cannot be
affirmed that the joining of one man to one woman is a portion of
'Eternal and Immutable Morality.'

Morality is an Institution of society, but not an arbitrary
institution.

8. Before adducing the proofs in support of the position above
assumed, namely, that Utility or Human Happiness, with certain
limitations, is the _proper_ criterion of Morality, it is proper to
enquire, what sort of evidence the Ethical Standard is susceptible of.

Hitherto, the doctrine of Utility has been assumed, in order to be
fully stated. We must next review the evidence in its favour, and the
objections urged against it. It is desirable, however, to ask what
kind of proof should be expected on such a question.

In the Speculative or Theoretical sciences, we prove a doctrine by
referring it to some other doctrine or doctrines, until we come at
last to some assumption that must be rested in as ultimate or final.
We can prove the propositions of Euclid, the law of gravitation, the
law of atomic proportions, the law of association; we cannot prove our
present sensations, nor can we demonstrate that what has been, will
be. The ultimate data must be accepted as self-evident; they have no
higher authority than that mankind generally are disposed to accept
them.

In the practical Sciences, the question is not as to a principle of
the order of nature, but as to an _end_ of human action. There may be