Since memory is the foundation of all mental operations, we have given to it the first place in the present discussion. And that the Japanese have a fair degree of memory argues well for the prospect of high attainment in other directions. With this in mind, we naturally ask whether they show any unusual proficiency or deficiency in the acquisition of foreign languages? In view of her protracted separation from the languages of other peoples, should we not expect marked deficiency in this respect? On the contrary, however, we find that tens of thousands of Japanese students have acquired a fairly good reading knowledge of English, French, and German. Those few who have had good and sufficient teaching, or who have been abroad and lived in Occidental lands, have in addition secured ready conversational use of the various languages. Indeed, some have contended that since the Japanese learn foreign languages more easily than foreigners learn Japanese, they have greater linguistic powers than the foreigner. It should be borne in mind, however, that in such a comparison, not only are the time required and the proficiency; attained to be considered, but also the inherent difficulty of the language studied and the linguistic helps provided the student. I have come gradually to the conclusion that the Japanese are neither particularly gifted nor particularly deficient in powers of language acquisition. They rank with Occidental peoples in this respect. To my mind language affords one of the best possible proofs of the general contention of this volume that the characteristics which distinguish the races are social rather than biological. The reason why the languages of the different races differ is not because the brain-types of the races are different, but only because of the isolated social evolution which the races have experienced. Had it been possible for Japan to maintain throughout the ages perfect and continuous social intercourse with the ancestors of the Anglo-Saxon race, while still maintaining biological isolation, _i.e._, perfect freedom from intermarriage, there is no reason to think that two distinct languages so different as English and Japanese would have arisen. The fact that Japanese children can accurately acquire English, and that English or American children can accurately acquire Japanese, proves conclusively that diversities of language do not rest on brain differences and brain heredity, but exclusively on social differences and social heredity.