POLITICAL ENTITIES Man's impulses and thoughts and acts result from the relation between his nature and the environment into which he is born.

The last chapter approached that relation (in so far as it affects politics) from the side of man's nature.

This chapter will approach the same relation from the side of man's political environment.
The two lines of approach have this important difference, that the nature with which man is born is looked on by the politician as fixed, while the environment into which man is born is rapidly and indefinitely changing.

It is not to changes in our nature, but to changes in our environment only--using the word to include the traditions and expedients which we acquire after birth as well as our material surroundings--that all our political development from the tribal organisation of the Stone Ages to the modern nation has apparently been due.
The biologist looks on human nature itself as changing, but to him the period of a few thousands or tens of thousands of years which constitute the past of politics is quite insignificant.

Important changes in biological types may perhaps have occurred in the history of the world during comparatively short periods, but they must have resulted either from a sudden biological 'sport' or from a process of selection fiercer and more discriminating than we believe to have taken place in the immediate past of our own species.