Undoubtedly some relation exists between all who live contemporaneously, and so it is possible to find some connection between the intellectual activity of men and their historical movements, just as such a connection may be found between the movements of humanity and commerce, handicraft, gardening, or anything else you please. But why intellectual activity is considered by the historians of culture to be the cause or expression of the whole historical movement is hard to understand. Only the following considerations can have led the historians to such a conclusion: (1) that history is written by learned men, and so it is natural and agreeable for them to think that the activity of their class supplies the basis of the movement of all humanity, just as a similar belief is natural and agreeable to traders, agriculturists, and soldiers (if they do not express it, that is merely because traders and soldiers do not write history), and (2) that spiritual activity, enlightenment, civilization, culture, ideas, are all indistinct, indefinite conceptions under whose banner it is very easy to use words having a still less definite meaning, and which can therefore be readily introduced into any theory.