ins, or the perfection or
due development of human character, all of which expressions, indeed,
when properly qualified and explained, I acknowledge to be the
equivalents of those for which I have stated a preference. And here
occurs a difficulty with respect to all these expressions and ideas. If
their meaning or content is not fixed, and specially if they are
undergoing a constant change, in the way of growth, with the progress of
reason and society, how can we employ them as a test of morality, which
is itself also a variable conception? Surely this is to make one
indefinite idea the gauge of another indefinite idea. The answer to this
question will, I trust, bring out clearly the nature of a moral test, as
well as the different modes of its application.

The ultimate origin of moral rules, I conceive, so far at least as
science can trace them, is to be found in the effort of men to adapt
themselves to the circumstances, social and physical, in which they are
placed. At first, probably, this process of adaptation was almost
automatic and unconscious, but, when men once began consciously to adapt
means to ends, they would soon begin to reflect on their acts, and to
ask themselves the reasons why they had selected this course of conduct
rather than another. The justifying reasons of their past acts, like the
impelling motives of their future acts, could have reference to nothing
but the convenience or gratification of themselves or those amongst whom
they lived. And the acts which they justified in themselves they would
approve of in others. Here, then, already we have a test consciously
applied to the estimation of conduct. Experience shews that this or that
action promotes some object which is included in the narrow conception
of well-being entertained by the primitive man. He, therefore, continues
to act in accordance with the rule which prescribes it, or the habit
from which it proceeds. And, in like manner, if he finds from experience
that the action does not promote that object, and he is free to exercise
his own choice, he desists from it and, perhaps, tries the experiment of
substituting another. Now, in these cases, it is plain that any judgment
which the man exercises independently, and apart from the society of
which he is a member, is guided solely by the consideration whether the
course of conduct is efficacious in attaining its end, that end being
part of his conception of the well-being of himself, his fa