First then, Herodotus gives us for the first time a reasoned scheme of ethnological criteria; and it marks at once an advance on that of Aeschylus, and an important modification of it. In the famous passage where the Athenians reject the proposals of Alexander of Macedon, and against immense inducements refuse to desert the Greek cause, they state as their inducement the fourfold bond which holds a nation together. ‘Greece,’ they reply,[93] ‘is of one blood; and of one speech; and has dwelling-places of gods in common, and sacrifices to them; and habits of similar customs’: and that is why the Athenians cannot betray their nation. Common descent, common language, common religion, and common culture: these are the four things which make a nation one; and, conversely, the things which, if unconformable, hold nations apart. To this analysis, modern ethnology has little or nothing to add. It might be said, as Professor Flinders Petrie has suggested,[94] that identity of religious beliefs is in the last resort only a peculiarly refined test of conformity of behaviour between man and man; and that community of culture, beyond dumb interchange of artefacts, is inconceivable without community of speech. But the mode of propagation, both of language and of religious observance, differs so greatly in kind from that of the transmission of material culture, that the forcible reduction of the four criteria of Herodotus to the two major criteria of Physique and Culture fails us in practice almost as soon as it is made. So far as Herodotus presents us with an ordered scheme of anthropological thought--with a science of anthropology, in fact--he is little, if at all, behind the best thought of our own day.