Yet in no national or racial group have cultural influences exercised so restrictive an influence as among the entire female sex. Not only has the larger world been closed to them, not only has popular opinion assumed that “no woman has it in her,” but the bearing and rearing of children has carried with it in the past the inescapable drudgery of housework. And this is “a field,” as Dr. Hollingworth points out, “where eminence is not possible.” It was Prudhon who sneered in response to a similar argument that “women could not even invent their distaff.” But we now know enough about the laws of invention to realize how unfair such sneering is. Professor Franz Boas and his school have long demonstrated that cultural achievement and mental ability are not necessarily correlated. For material culture, once it begins, tends to grow by accumulation and diffusion. Each generation adds to the existing stock of knowledge, and as the stock grows the harvests necessarily become greater. Modern man need have no greater mental ability than the men of the ice ages to explain why his improvements upon the myriad machines and tools that are his yield so much larger a harvest than the Paleolithic hunters’ improvements upon their few flint weapons and industrial processes. For, as Professor Ogburn has well shown (in “Social Change,” Part III) all invention contains two elements--a growing cultural base and inventive genius to work with the materials it furnishes. The number of new inventions necessarily grows with the cultural base. Even 50 times 100 make only 5000, but 2 times 1,000,000 make 2,000,000. Countless generations have added their share to the total material culture which is ours and which we shall hand down still more enriched to posterity. It must be at once obvious that there has been no such cultural growth in housework. Housework has long remained an individualized, non-cumulative industry, where daughter learns from mother the old ways of doing things. The small improvements and ingenuities which most housewives devise seldom find their way into the whole stream of culture. Thus it is that the recent great inventions which are slowly revolutionizing this last stronghold of petty individualism have come from the man-made world. Workers in electricity could more easily devise the vacuum cleaner than the solitary housewife; the electric washer, parquet floors, the tin can, quantity production of stockings, wool, clothing, bread, butter, and all the other instruments that have really made possible women’s emancipation have naturally come not from women’s minds (any more than from men’s) but from the growth of culture and the minds that utilize that growth for further expansion.