(b) The extension of working instruments has followed a logical evolution in the direction of growing complexity and perfection. Man, according to the observations of M. Bourdeau, has applied his creative activity to natural forces and has set them to work according to a regular order, viz.: (1) Human forces, the only ones available during the "state of nature" and the savage state. Before all else, man created weapons: the most circumscribed primitive races have invented engines for attack and defense--of wood, bone, stone, as they were able. Then the weapon became a tool by special adaptation:--the battle-club serves as a lever, the tomahawk as a hammer, the flint ax as a hatchet, etc. In this manner there is gradually formed an arsenal of instruments. "Inferior to most animals as regards certain work that would have to be done with the aid of our organic resources alone, we are superior to all as soon as we set our tools at work. If the rodents with their sharp teeth cut wood better than we can, we do it still better with the ax, the chisel, the saw. Some birds, with the help of a strong beak, by repeated blows, penetrate the trunk of a tree: but the auger, the gimlet, the wimble do the same work better and more quickly. The knife is superior to the carnivore's teeth for tearing meat; the hoe better than the mole's paw for digging earth, the trowel than the beaver's tail for beating and spreading mortar. The oar permits us to rival the fish's fin; the sail, the wing of the bird. The distaff and spindle allow our imitating the industry of insect spinners; etc. Man thus reproduces and sums up in his technical contrivances the scattered perfections of the animal world. He even succeeds in surpassing them, because, in the form of tools, he uses substances and combinations of effects that cannot figure as part of an organism."[127] It is scarcely likely that most of these inventions arose from a voluntary imitation of animals: but even supposing such an origin, there would still remain a fine place for personal creative work. Man has produced by conscious effort what life realizes by methods that escape us; so that the creative imagination in man is a _succedaneum_ of the generative powers of nature. (2) During the pastoral stage man brought animals under subjection and discipline. An animal is a machine, ready-made, that needs only to be trained to obedience; but this training has required and stimulated all sorts of inventions, from the harness with which to equip it, to the chariots, wagons, and roads with which and on which it moves. (3) Later, the natural motors--air and water--have furnished new material for human ingenuity, e.g., in navigation; wind- and water-mills, used at first to grind grain, then for a multitude of uses--sawing, milling, lifting hammers; etc.