Now, while undoubtedly in these passages we may recognise the first anticipation of many of the most modern principles of research, we must remember how essentially limited is the range of the _archæologia_, and how no theory at all is offered on the wider questions of the general conditions of the rise and progress of humanity, a problem which is first scientifically discussed in the _Republic_ of Plato. And at the outset it must be premised that, while the study of primitive man is an essentially inductive science, resting rather on the accumulation of evidence than on speculation, among the Greeks it was prosecuted rather on deductive principles. Thucydides did, indeed, avail himself of the opportunities afforded by the unequal development of civilisation in his own day in Greece, and in the places I have pointed out seems to have anticipated the comparative method. But we do not find later writers availing themselves of the wonderfully accurate and picturesque accounts given by Herodotus of the customs of savage tribes. To take one instance, which bears a good deal on modern questions, we find in the works of this great traveller the gradual and progressive steps in the development of the family life clearly manifested in the mere gregarious herding together of the Agathyrsi, their primitive kinsmanship through women in common, and the rise of a feeling of paternity from a state of polyandry. This tribe stood at that time on that borderland between umbilical relationship and the family which has been such a difficult point for modern anthropologists to find. The ancient authors, however, are unanimous in insisting that the family is the ultimate unit of society, though, as I have said, an inductive study of primitive races, or even the accounts given of them by Herodotus, would have shown them that the _νεοττιὰ ἴδια_ of a personal household, to use Plato’s expression, is really a most complex notion appearing always in a late stage of civilisation, along with recognition of private property and the rights of individualism. Philology also, which in the hands of modern investigators has proved such a splendid instrument of research, was in ancient days studied on principles too unscientific to be of much use. Herodotus points out that the word _Eridanos_ is essentially Greek in character, that consequently the river supposed to run round the world is probably a mere Greek invention. His remarks, however, on language generally, as in the case of _Piromis_ and the ending of the Persian names, show on what unsound basis his knowledge of language rested.