Evolution is a name comprehending certain theories which seek to account for all operations of nature as carried on according to fixed laws by means of forces resident in nature. Prof. J. LeConte of the University of California defines evolution as: "Continuous progressive change according to certain laws and by means of resident forces". Evolution is a theory, a philosophy, it is not a science. The theory is called organic evolution in its relation to living forms (plant and animal life), cosmic evolution, inasmuch as attempts have been made to account by certain laws and the working of resident forces for the development of the universe, —the earth, the sun, and the starry heavens. Also the development of society, of religion, morals, politics, art, and mechanical inventions is accounted for on the theory that there are forces which, acting according to certain laws, have through many changes made human life and institutions as we see them today.