The difference, on the other hand, between one man's environment and that of other men can be arranged on no curve and remembered or forecasted by no expedient.

Buckle, it is true, attempted to explain the present and prophesy the future intellectual history of modern nations by the help of a few generalisations as to the effect of that small fraction of their environment which consisted of climate.

But Buckle failed, and no one has attacked the problem again with anything like his confidence.
We can, of course, see that in the environment of any nation or class at any given time there are some facts which constitute for all its members a common experience, and therefore a common influence.

Climate is such a fact, or the discovery of America, or the invention of printing, or the rates of wages and prices.

All nonconformists are influenced by their memory of certain facts of which very few churchmen are aware, and all Irishmen by facts which most Englishmen try to forget.