The institutions and practices of a people are a product of the mind; and if the early and spontaneous products of mind are everywhere of the same general pattern as the later manifestations, only less developed, refined, and specialized, it may well be that failure to progress equally is not due to essential unlikeness of mind, but to conditions lying outside the mind. Another test of mental ability which deserves special notice is mechanical ingenuity. Our white pre-eminence owes much to this faculty, and the lower races are reckoned defective in it. But the lower races do invent, and it is doubtful whether one invention is ever much more difficult than another. On the psychological side, an invention means that the mind sees a roundabout way of reaching an end when it cannot be reached directly. It brings into play the associative memory, and involves the recognition of analogies. There is a certain likeness between the flying back of a bough in one's face and the rebound of a bow, between a serpent's tooth and a poisoned arrow, between floating timber and a raft or boat; and water, steam, and electricity are like a horse in one respect--they will all make wheels go around, and do work. Now, the savage had this faculty of seeing analogies and doing things in indirect ways. With the club, knife, and sword he struck more effectively than with the fist; with hooks, traps, nets, and pitfalls he understood how to seize game more surely than with the hands; in the bow and arrow, spear, blow-gun, and spring-trap he devised motion swifter than that of his own body; he protected himself with armor imitated from the hides and scales of animals, and turned their venom back on themselves. That the savage should have originated the inventive process and carried it on systematically is, indeed, more wonderful than that his civilized successors should continue the process; for every beginning is difficult. When occupations become specialized and one set of men has continually to do with one and only one set of machinery and forces, the constant play of attention over the limited field naturally results in improvements and the introduction of new principles. Modern inventions are magnificent and seem quite to overshadow the simpler devices of primitive times; but when we consider the precedents, copies, resources, and accumulated knowledge with which the modern investigator works, and, on the other hand, the resourcelessness of primitive man in materials, ideas, and in the inventive habit itself, I confess that the bow and arrow seems to me the most wonderful invention in the world.