As a geologist Sir John Lubbock may be entitled to rely mainly upon the geological evidence of a palæolithic age;[241] but as an ethnologist dealing with history and writing on the subject of tradition, his argument, however incontrovertible he may deem it, sinks to the second rank; and secondary I shall take the liberty of considering it. On the same grounds, though I think with more reason, that Sir J. Lubbock seeks to be relieved from "the embarrassing interference of tradition" ("Pre-historic Times," p. 336), I protest, when tradition is the subject-matter of the discussion, against a geological argument being brought to take the ground from under our feet! [241] It may perhaps be doubtful to what extent Sir J. Lubbock maintains his theory of a Stone Age; although Sir John formally excludes China and Japan from the argument, he nevertheless appears to me to assume the existence of universal transitional periods through which the human race necessarily passed. "It would appear that pre-historic archæology may be divided into four great epochs. Firstly, that of the Drift: when man shared the possession of Europe with the mammoth, &c. This we may call the 'palæolithic period.' Secondly, the later or polished Stone Age; a period, &c. Thirdly, the Bronze Age, &c. Fourthly, the Iron Age." Sir John adds, certainly--"In order to prevent misapprehension, it may be well to state at once, that for the present I only apply this classification to Europe, though in all probability it might be extended also to the neighbouring parts of Asia and Africa. As regards other civilised countries, China and Japan for instance, we as yet know nothing of their pre-historic archæology. [I should rather say, as we as yet have no reason to suppose that they have ever lost the knowledge of metals.] It is evident also that some nations, such as the Fuegians, Andamaners, &c., are _even now_ only in an age of stone. But even in this limited sense, the above classification has not met with general acceptance; there _are still some_ archæologists who believe that the arms and implements--stone, bronze, and iron--were used contemporaneously."--_Pre-historic Times_, pp. 2, 3. I think that the concluding sentence makes it quite clear that Sir John assumes the existence of universal progressive periods as above. In any case it may be proved in this way. Sir John argues upon the hypothesis of the unity of the human race; and I also think that he will not refuse the unbroken testimony to the fact of the civilisation of Europe from Asia. Either, then, the _first_ colonisation took place when Asia was in the state of the "Drift," or in the "later polished Stone Age," or else the migration left Asia with the knowledge of bronze or iron.