Man and nature are the two primary factors in production. In the process of creating utilities to gratify man's wants each acts upon the other and with the other. Man acts upon nature, as for example in digging the Panama canal, and brings two countries thousands of miles nearer together, thus making it easier for each to get the products of the other. Nature acts upon man, as for example in acclimating him to a new environment and thus making it possible for him to feel comfortable with a smaller supply of clothing than he at first found necessary. Man and nature work together in production, as for example in the growing of wheat, where nature furnishes not only the material but also the vital forces, but where the wheat would not grow abundantly if man did not take the trouble to sow the seed so that it would be ready to sprout at the proper season, and to till the soil so that the forces of nature could work at their best in the production of the crop.