"Historically division of labor originates in two facts of nature: the inequality of human abilities and the variety of the external conditions of human life on the earth. These two facts are really one: the diversity of Nature, which does not repeat itself but creates the universe in infinite, inexhaustible variety….
These two conditions … are indeed such as almost to force the division of labor on mankind. Old and young, men and women cooperate by making appropriate use of their various abilities. Here also is the germ of the geographical division of labor; man goes to the hunt and woman to the spring to fetch water. Had the strength and abilities of all individuals and the external conditions of production been everywhere equal the idea of division of labor could never have arisen … No social life could have arisen among men of equal natural capacity in a world which was geographically uniform….
Once labor has been divided, the division itself exercises a differentiating influence. The fact that labor is divided makes possible further cultivation of individual talent and thus cooperation becomes more and more productive. Through cooperation men are able to achieve what would have been beyond them as individuals….
The greater productivity of work under the division of labor is a unifying influence. It leads men to regard each other as comrades in a joint struggle for welfare, rather than as competitors in a struggle for existence.”