an uncertainty about details,--whether, for example, under given
circumstances such and such a moral principle is to be enforced, or whether
in some cases there may not be a conflict of duties: these are the
exceptions to the ordinary rules of morality, important, indeed, but not
extending to the one thousandth or one ten-thousandth part of human
actions. This is the domain of casuistry. Secondly, the aspects under
which the most general principles of morals may be presented to us are many
and various. The mind of man has been more than usually active in thinking
about man. The conceptions of harmony, happiness, right, freedom,
benevolence, self-love, have all of them seemed to some philosopher or
other the truest and most comprehensive expression of morality. There is
no difference, or at any rate no great difference, of opinion about the
right and wrong of actions, but only about the general notion which
furnishes the best explanation or gives the most comprehensive view of
them. This, in the language of Kant, is the sphere of the metaphysic of
ethics. But these two uncertainties at either end, en tois malista
katholou and en tois kath ekasta, leave space enough for an intermediate
principle which is practically certain.

The rule of human life is not dependent on the theories of philosophers:
we know what our duties are for the most part before we speculate about
them. And the use of speculation is not to teach us what we already know,
but to inspire in our minds an interest about morals in general, to
strengthen our conception of the virtues by showing that they confirm one
another, to prove to us, as Socrates would have said, that they are not
many, but one. There is the same kind of pleasure and use in reducing
morals, as in reducing physics, to a few very simple truths. And not
unfrequently the more general principle may correct prejudices and
misconceptions, and enable us to regard our fellow-men in a larger and more
generous spirit.