It affords an arena in which the restless and adventurous members of a national body can have their fling without dangerous consequences, while at the same time it satisfies the desire of a people for some evidence of and opportunity for national expansion.

The nations which, one after another, have recognized the limits of their expansion in Europe have been those which have adopted a more or less explicit policy of colonial acquisition.

Spain was, indeed, a great colonial power at a time when her policy in Europe continued to be aggressive; but her European aggressions soon undermined her national vitality, and her decadence in Europe brought her colonial expansion to a standstill.

Portugal and Holland were too small to cherish visions of European aggrandizement, and they naturally sought an outlet in Asia and Africa for their energies.

After Great Britain had passed through her revolutionary period, she made rapid advances as a colonial power, because she realized that her insular situation rendered a merely defensive European policy obligatory.