For Emerson, the word "commodity" means a physical necessity. Using this definition, he discusses briefly how nature supports our earthly existence. Different elements, ranging from resources like metals, plants, and animals to the basic elements of earth, air, fire, and water, nourish earth's inhabitants. This process furthers the essay's theme of progress based on evolution, for the wind, the sun, the rain, the plants, and the animals, all work together to better mankind. And by describing the art made by humans as being reproductions of nature, Emerson suggests that by creating art, humanity fits itself into this pattern of integration.