ned into
intellectual muscle. Worse still, our system is fatal to that vigour of
physique needful to make intellectual training available in the struggle
of life. Yet a good digestion, a bounding pulse, and high spirits are
elements of happiness which no external advantages can outbalance.

Perhaps nothing will so much hasten the time when body and mind will
both be adequately cared for, as a diffusion of the belief that the
preservation of health is a duty. Few seem conscious that there is such
a thing as physical morality. Men's habitual words and acts imply the
idea that they are at liberty to treat their bodies as they please.
Disorders entailed by disobedience to nature's dictates, they regard
simply as grievances; not as the effects of a conduct more or less
flagitious. Though the evil consequences inflicted on their dependents,
and on future generations, are often as great as those caused by time,
yet they do not think themselves in any degree criminal. It is true
that, in the case of drunkenness, the viciousness of a bodily
transgression is recognised; but none appear to infer that, if this
bodily transgression is vicious, so, too, is every bodily transgression.
The fact is, that all breaches of the laws of health are _physical
sins._ When this is generally seen, then, and perhaps not till then,
will the physical training of the young receive the attention which it
deserves.

Principles of Biology

In 1860 Spencer commenced a connected series of philosophical
works, designed to unfold in their natural order the principles of
biology, psychology, sociology and morality. "Principles of
Biology" was published in 1864, and aims to set forth, the general
truths of biology as illustrative of, and as interpreted by the
laws of evolution. It was revised in 1899.

_Proximate Definition of Life_

To those who accept the general doctrine of evolution, it needs scarcely
to be pointed out that classifications are subjective conceptions which
have no absolute demarcations in nature corresponding to them.
Consequently in attempting to define anything complex we can scarcely
ever avoid including more than was intended, or leaving out something
that should be taken in. Thus it happens that on seeking a definition of
life there is great difficulty in finding one that is neither more nor
less than sufficient. As the best mode of determining the general
characteristics of vitality, let us