It is possible that my use of the word "construct," my saying that the object is a thing which each of us constructs at the suggestion of certain sense-stimuli, may lead some to suppose that the process is in some sense an arbitrary one. This, however, would be a misconception. The process under normal conditions is just as inevitable as is, under normal conditions, the fall of a stone to the ground. The law of construction for human-folk is as much a law of nature as the law of gravitation. Both laws are condensed statements of the facts of the case. There is nothing arbitrary, lawless, or unnatural in the one or the other; the phrase merely emphasizes the essential presence of the mental factor. If this principle be once thoroughly grasped, it will be seen how shallow and misleading is the view that the world is just reflected in consciousness unchanged as in a mirror, or faithfully photographed as on a sensitive plate. This is to reduce the human mind, which is surely no whit _less_ complex than the human body, to the condition of a mere passive recipient instead of a vital and active agent in the construction of man's world. The next point we have to consider is why we believe, as you and I practically do believe, that the world of phenomena exists as such, not merely for you and for me, but for man. Is it not because we believe in the practical unity of mankind? Is it not because we believe that, greatly as the conceptual and intellectual superstructure may differ in different individuals, the perceptual basis and foundation are practically identical? The senses and sense-organs give, in all normal individuals, sense-data, which differ only within comparatively narrow limits; and though the intellectual and moral world of the Bushman and the North Australian may differ profoundly from those of Shakespeare and Pascal, the perceptual world is, we have every reason to suppose, within these narrow limits, the same. This we may fairly believe; but even so there must be, nay, we know that there are, very great differences in the interpretation of the perceptual world. The individual cannot divest himself of the intellectual and conceptual part of his nature. We, for whom phenomena are more or less conditioned by science, find it difficult to think ourselves into the position of the savage, whose perceptual world is conditioned by crude superstition. The elements of his perceptual world are the same as ours, but the light of knowledge in which we view them is, for him, very dim. When we try to realize his world we find it exceedingly difficult.