The ablest and most influential development of the argument from
evolution to Progress was the work of Spencer. He extended the principle
of evolution to sociology and ethics, and was the most conspicuous
interpreter of it in an optimistic sense. He had been an evolutionist
long before Darwin's decisive intervention, and in 1851 he had published
his Social Statics, which, although he had not yet worked out the
evolutionary laws which he began to formulate soon afterwards and was
still a theist, exhibits the general trend of his optimistic philosophy.
Progress here appears as the basis of a theory of ethics. The title
indicates the influence of Comte, but the argument is sharply opposed to
the spirit of Comte's teaching, and sociology is treated in a new
way. [Footnote: Social Statics, or the Conditions Essential to Human
Happiness specified, and the first of them developed, is the full
title.]

Spencer begins by arguing that the constancy of human nature, so
frequently alleged, is a fallacy. For change is the law of all things,
of every single object as well as of the universe. "Nature in its
infinite complexity is ever growing to a new development." It would be
strange if, in this universal mutation, man alone were unchangeable,
and it is not true. "He also obeys the law of indefinite variation."
Contrast the houseless savages with Newtons and Shakespeares; between
these extremes there are countless degrees of difference. If then
humanity is indefinitely variable, perfectibility is possible.

In the second place, evil is not a permanent necessity. For all evil
results from the non-adaptation of the organism to its conditions;
this is true of everything that lives. And it is equally true that evil
perpetually tends to disappear. In virtue of an essential principle of
life, this non-adaptation of organisms to their conditions is ever being
rectified, and one or both continue to be modified until the adaptation
is perfect. And this applies to the mental as well as to the physical
sphere.

In the present state of the world men suffer many evils, and this shows
that their characters are not yet adjusted to the social state. Now the
qualification requisite for the social state is that each individual
shall have such desires only as may fully be satisfied without trenching
upon the ability of others to obtain similar satisfaction. This
qualification is not yet fulfilled, because civilised man retains some
of the charact