One could easily imagine a world in which economic activities were individual activities in the sense that each person was active only in providing for his own needs. But the world in which we live is not such a world. Here economic activities are social activities. The individual helps other individuals to secure the things which they need, and they in turn help him to secure the things which he needs. Ten thousand persons assisted you in the preparation of to-day's dinner and you repay the obligation by working for ten thousand other persons who indirectly pay the price of the dinner to the first ten thousand persons. Our economic life is a life of cooperation. Economic activities are social activities, and economics or the science of economic activities is a social science.