In fact, mankind have been in existence for so many centuries, and their physical, moral, mental, and spiritual characteristics were so evidently implanted in them by the Almighty, that it seems difficult to see how any one, except the Almighty himself, can change these characteristics and their resulting conduct. It is a common saying that a man cannot lift himself over the fence by his boot straps, though he can jump over the fence, if it is not too high. This saying recognizes the fact that "a material system can do no work on itself"; but needs external aid. When a man pulls upward on his boot straps, the upward force that he exerts is exactly balanced by the downward reaction exerted by his boot straps; but when he jumps, the downward thrust of his legs causes an equal reaction of the earth, which exerts a direct force upward upon the man; and it is this external force that moves him over the fence. It is this external force, the reaction of the earth or air or water, which moves every animal that walks, or bird that flies, or fish that swims. It is the will of the Almighty, acting through the various stimuli of nature, that causes the desire to walk, and all the emotions and actions of men. If He shall cause any new force to act on men, their line of conduct will surely change. But if He does not--how can it change, or be changed; how can the human race turn about, by means of its own power only, and move in a direction the reverse from that in which it has been moving throughout all the centuries of the past? These considerations seem to indicate that nations, regarded in their relation toward each other, will go on in the direction in which they have been going unless acted upon by some external force. Will civilization, commerce, or Christianity impart that force? Inasmuch as civilization is merely a condition in which men live, and an expression of their history, character and aims, it is difficult to see how it could of itself act as an external force, or cause an external force to act. "Institutions and laws," says Le Bon, again, "are the outward manifestation of our character, the expression of its needs. Being its outcome, institutions and laws cannot change this character."