Few men, except those who are accustomed to it, could walk on the ridge of a high house without falling down. Yet the same men could walk with perfect security, on similar footing, placed on the ground. What is the interpretation of this contrariety? Fear, we are told, is that which makes the {374} inexperienced person fall. But fear implies belief. There is nothing, however, in the case, but the intense association of the idea of his falling, with his sight of the position in which he is placed. In some persons this idea is so easily excited, that they cannot look down from even a very moderate height, without feeling giddy, as they call it; that is, without having the apprehension; in other words, the belief, of falling.[11*] [Mill's footnote 11: The same account, in substance, of some of the last of these phenomena, is given by Dr. Brown; and it may aid the conceptions of the learner, to observe the different modes of exposition used by two different writers. "There can be no question, that he who travels in the same carriage, with the same external appearances of every kind by which a robber could be tempted or terrified, will be in equal danger of attack, whether he carry with him little of which he can be plundered, or such a booty as would impoverish him if it were lost. But there can be no question also, that though the probabilities of danger be the same, the fear of attack would, in these two cases, be very different; that, in the one case, he would laugh at the ridiculous terror of any one who journeyed with him, and expressed much alarm at the approach of evening; and that, in the other case, his own eye would watch suspiciously every horseman who approached, and would feel a sort of relief when he observed him pass carelessly and quietly along at a considerable distance behind.