A still more important occurrence was the invention of making fire. Probably less inventive effort was needed for this than for the bow and arrow; for fire could be seen in the lightning and in trees struck by lightning, and in the sparks that came forth when two hard stones were struck together. The discovery of fire may have been made by accident; but this does not mean that no invention was needed for devising and producing the means whereby fire could be produced at will. To note the fact of a phenomenon, say the production of fire when stones are accidentally struck together, or the falling of an apple from a tree, requires no special effort, and of itself brings forth no benefit; but to reason from the appearance of the sparks to the production of an apparatus for making fire at will; or to reason from the falling of an apple to the enunciation of Newton's Law of Gravitation, is the kind of successful mental effort that has produced the effects which it is the endeavor of this humble book to indicate. These effects have combined as progress has advanced, to put civilized man in a position relatively to his natural surroundings very different from that held by primeval man, and very different from that held by the brutes, both in primeval days and now. Evidently, the effects have been made possible by some faculty possessed by man and not by brutes. This faculty is usually called reason, and is held to be a faculty by means of which man can infer cause from effect, and effect from cause, and can remember events and facts to a degree sufficient to enable him to hold them in his mind, while reasoning about them. But it seems impossible to explain the advent of even the oldest and simplest inventions by the possession of reason only, using the word reason in its ordinary sense; for it is obvious that no matter how clearly a man could reason as between cause and effect, no matter how great a student of all phenomena he might be, no matter how good a memory he might have, he might nevertheless live for many years and never invent anything. In fact, we see men at the present day who possess great knowledge, splendid energy, keen powers of analysis, high courage, and even great administrative talent, and yet who are obviously deficient in originality, who seem to possess the constructive faculty in only a small degree, and who seem incapable of taking any step forward except on paths that have been plainly trod before.