n," the human constitution as it
exists to-day, being the result of a long evolution and containing a
large animal element, cannot furnish the basis of rational morality. The
conception which has come down from antiquity to modern times, of a
harmonious activity of all the organs, is no longer appropriate to
mankind. Organs which are in course of atrophy must not be re-awakened,
and many natural characters which, perhaps, were useful in the case of
animals, must be made to disappear in men.

Human nature which, like the constitutions of other organisms, is
subject to evolution, must be modified according to a definite ideal.
Just as a gardener or stock-raiser is not content with the existing
nature of the plants and animals with which he is occupied, but modifies
them to suit his purposes, so also the scientific philosopher must not
think of existing human nature as immutable, but must try to modify it
for the advantage of mankind. As bread is the chief article in the human
food, attempts to improve cereals have been made for a very long time,
but in order to obtain results much knowledge is necessary. To modify
the nature of plants, it is necessary to understand them well, and it is
necessary to have an ideal to be aimed at. In the case of mankind the
ideal of human nature, towards which we ought to press, may be formed.
In my opinion this ideal is "orthobiosis"--that is to say, the
development of human life, so that it passes through a long period of
old age in active and vigorous health, leading to a final period in
which there shall be present a sense of satiety of life, and a wish for
death.

Just as we must study the nature of plants before trying to realise our
ideal, so also varied and profound knowledge is the first requisite for
the ideal of moral conduct. It is necessary not only to know the
structure and functions of the human organism, but to have exact ideas
on human life as it is in society. Scientific knowledge is so
indispensable for moral conduct that ignorance must be placed among the
most immoral acts. A mother who rears her child in defiance of good
hygiene, from want of knowledge, is acting immorally towards her
offspring, notwithstanding her feeling of sympathy. And this also is
true of a government which remains in ignorance of the laws which
regulate human life and human society.

If the human race come to adopt the principles of orthobiosis, a
considerable change in the qualities of men of d