which their ends
could be reached." ("English literature and society in the eighteenth
century", London, 1904, page 187.) And Kant supposed that every man
would find the "categorical imperative" in his consciousness, when he
came to sober reflexion, and that all would have the same qualifications
to follow it. But if continual variations, great or small, are going on
in human nature, it is the duty of ethics to make allowance for them,
both in making claims, and in valuing what is done. A new set of ethical
problems have their origin here. (Cf. my paper, "The law of relativity
in Ethics," "International Journal of Ethics", Vol. I. 1891, pages
37-62.) It is an interesting fact that Stuart Mill's book "On Liberty"
appeared in the same year as "The Origin of Species". Though Mill agreed
with Bentham about the original equality of all men's endowments, he
regarded individual differences as a necessary result of physical and
social influences, and he claimed that free play shall be allowed to
differences of character so far as is possible without injury to other
men. It is a condition of individual and social progress that a man's
mode of action should be determined by his own character and not
by tradition and custom, nor by abstract rules. This view was to be
corroborated by the theory of Darwin.

But here we have reached a point of view from which the criticism,
which in recent years has often been directed against Darwin--that
small variations are of no importance in the struggle for life--is of
no weight. From an ethical standpoint, and particularly from the
ethical standpoint of Darwin himself, it is a duty to foster individual
differences that can be valuable, even though they can neither be of
service for physical preservation nor be physically inherited. The
distinction between variation and mutation is here without importance.
It is quite natural that biologists should be particularly interested in
such variations as can be inherited and produce new species. But in the
human world there is not only a physical, but also a mental and social
heredity. When an ideal human character has taken form, then there
is shaped a type, which through imitation and influence can become an
important factor in subsequent development, even if it cannot form a
species in the biological sense of the word. Spiritually strong
men often succumb in the physical struggle for life; but they can
nevertheless be victorious through the typical