It is sometimes urged, with considerable justice, that modern historians take too little notice of the religious factor in social life. Distinguished writers may even be found protesting that the differences among Christian sects interest them no more than the quarrel between Tweedledum and Tweedledee: yet these same men would never dream of ignoring racial or climatic differences. The attitude of Europe in general towards Life after Death was almost as universal in its main outlines, and almost as different from that of a great part of modern Europe, as are the heat of Africa, and the skin of an Ethiopian, in contrast with what we feel and see around us everywhere in Britain. It is irrelevant whether our own personal preference is for a tropical or temperate climate, for white skins or black; the point is that, in thinking or writing of African society, we must remember that our common human motives are at work there under, for us, most uncommon and peculiar conditions. So was it also in the Middle Ages. Within a spiritual climate very different from our own, among men hedged round by certain limitations over which modern thought bears us as easily as the aeroplane crosses the sea, the same elementary social forces were at work as to-day; and the main conflicts of thought were essentially the same. The struggle was always, at bottom, between the conservative and the progressive mind, each with those same qualities and defects which each shows at the present day.