As a general rule, man strives to avoid labor. Love for work is not at all an inborn characteristic: it is created by economic pressure and social education. One may even say that man is a fairly lazy animal. It is on this quality, in reality, that is founded to a considerable extent all human progress; because if man did not strive to expend his energy economically, did not seek to receive the largest possible quantity of products in return for a small quantity of energy, there would have been no technical development or social culture.