ects in an unsettled
tribe; but where there grows up a fixed and multiplying community, these
differentiations become permanent, and increase with each generation. A
larger population, involving a greater demand for every commodity,
intensifies the functional activity of each specialised person or class;
and this renders the specialisation more definite where it already
exists, and establishes it where it is nascent. By increasing the
pressure on the means of subsistence, a larger population again augments
these results; seeing that each person is forced more and more to
confine himself to that which he can do best, and by which he can gain
most. This industrial progress, by aiding future production, opens the
way for a further growth of population, which reacts as before: in all
which the multiplication of effects is manifest. Presently, under these
same stimuli, new occupations arise. Competing workers, ever aiming to
produce improved articles, occasionally discover better processes or raw
materials. In weapons and cutting tools, the substitution of bronze for
stone entails upon him who first makes it a great increase of demand--so
great an increase that he presently finds all his time occupied in
making the bronze for the articles he sells, and is obliged to depute
the fashioning of these to others: and, eventually, the making of
bronze, thus gradually differentiated from a pre-existing occupation,
becomes an occupation by itself.

But now mark the ramified changes which follow this change. Bronze soon
replaces stone, not only in the articles it was first used for, but in
many others--in arms, tools, and utensils of various kinds; and so
affects the manufacture of these things. Further, it affects the
processes which these utensils subserve, and the resulting
products--modifies buildings, carvings, dress, personal decorations. Yet
again, it sets going sundry manufactures which were before impossible,
from lack of a material fit for the requisite tools. And all these
changes react on the people--increase their manipulative skill, their
intelligence, their comfort,--refine their habits and tastes. Thus the
evolution of a homogeneous society into a heterogeneous one, is clearly
consequent on the general principle, that many effects are produced by
one cause.

Our limits will not allow us to follow out this process in its higher
complications: else might we show how the localisation of special
industries in special par