=The Method of Hobbes.= Hobbes made the method of Galileo his own. He believed that all knowledge is rooted in mathematics. There is one true method of treating all subjects: the mathematical calculation of them as motions of bodies. Knowledge consists in using words as the signs of experience and in reckoning with them. Scientific thought is the combination of signs. It is the rationalizing of our experiences. Science has a truth in itself and stands as a rationally organized world, quite different from the world of experience which it has organized. The world of bodies in causally related motions is such an organized world, the most systematized and most simply constructed world that science can devise. But how does the scientist proceed? He begins with a phenomenon, which is a body in motion, and finds out the causes of the phenomenon, which causes are nothing more nor less than the elements of the phenomenon in question. Then the scientist proceeds from the causes to other phenomenal effects. These new effects are like the original phenomenon and its causes,――bodies in motion. Thus the world of the scientist is a world of causes and effects, for “the natural reason of man is busily flying up and down among the creatures, and bringing back a true report of their order, causes, and effects.” Thus we find Hobbes to be a nominalist (see vol. i, p. 358) who, nevertheless, used the deductive method――rather a strange combination. Like all his English successors, he employed induction and deduction, but the two processes never became fused.[24] Moreover for induction he has no method. The order in which the writings of Hobbes appeared seems to have been the sport of outward events, for they were not written according to his original plan. On his return from his third journey to the Continent (1638), Hobbes, then fifty years old, had adopted the mechanical theory and had planned his philosophy. His comprehensive work was to be called the _Elements of Philosophy_, and was to be divided into three parts: _De Corpore_, treating physical bodies; _De Homine_, treating man as a psychological individual; _De Cive_, treating man as the citizen of a State. Hobbes’s philosophy was therefore to be a universal philosophy, and he intended to bring his works out in logical order――first, the science of physics, then of human nature, and last of society. However, the growing disturbances in the political world at that time moved him to publish several treatises on politics first, and his physics and psychology more than fifteen years later.