Just watch a man walking, if he is a proper man, and see the business of it: how he expresses his pride, or his determination, or his tenacity, or his curiosity, or perhaps his very purpose in his stride! Well, all that business of walking that you are looking at is a piece of extraordinarily skilful trick-acting, such that were the animal not known to do it you would swear he could never be trained to it by any process, however lengthy, or however minute, or however strict. This is what happens when a man walks: first of all he is in stable equilibrium, though the arc of stability is minute. If he stands with his feet well apart, his centre of gravity (which is about half way up him or a little more) may oscillate within an arc of about five degrees on either side of stability and tend to return to rest. But if it oscillates beyond that five degrees or so, the stability of his equilibrium is lost, and down he comes. Men have been known to sleep standing up without a support, especially on military service, which is the most fatiguing thing in the world; but it is extremely rare, and you may say of a man so standing, even with his feet well spread, that he is already doing a fine athletic feat. But wait a moment: he desires to go, to proceed, to reach a distant point, and instead of going on all fours, where equilibrium would indeed be stable, what does he do? He deliberately lifts one of his supports off the ground, and sends his equilibrium to the devil; at the same time he leans a little forward so as to make himself fall towards the object he desires to attain. You do not know that he does this, but that is because you are a man and your ignorance of it is like the ignorance in which so many really healthy people stand to religion, or the ignorance of a child who thinks his family established for ever in comfort, wealth and security. What you really do, man, when you want to get to that distant place (and let this be a parable of all adventure and of all desire) is to take an enormous risk, the risk of coming down bang and breaking something: you lift one foot off the ground, and, as though that were not enough, you deliberately throw your centre of gravity forward so that you begin to fall. That is the first act of the comedy. The second act is that you check your fall by bringing the foot which you had swung into the air down upon the ground again.