Page:Popular Science Monthly Volume 6.djvu/539

Rh girl of some seven, who did not know what a shadow was, and to whom I could give no conception of its true nature.

On ignoring acquired ideas, we shall see this difficulty to be quite natural. A thing having outlines, and differing from surrounding things in color, and especially a thing which moves, is, in other cases, a reality. Why is not this a reality? The conception of it, merely a negation of light, is a conception not to be framed until after the behavior of light is in some degree understood. It is true that the uncultured among ourselves, without clearly formulating the truth that light, proceeding in straight lines, necessarily leaves unlighted spaces behind opaque objects, nevertheless come to regard a shadow as naturally attending an object exposed to light, and as not being any thing real. But this is one of the countless cases in which inquiry is set at rest by a verbal explanation. "It's only a shadow," is the answer given in early days; and this answer, repeatedly given, deadens wonder and stops further thought.

But the primitive man, with no one to answer his questions, and without ideas of physical causation, necessarily concludes a shadow to be an actual existence, which belongs in some way to the person casting it. He simply accepts the facts. Whenever the sun or moon is visible, he sees this attendant thing which rudely resembles him in shape, which moves when he moves, which now goes before him, now keeps by his side, now follows him, which lengthens and shortens as the ground inclines this way or that, and which distorts itself in strange ways as he passes by irregular surfaces. True he cannot see it in cloudy weather; but, in the absence of a physical interpretation, this simply proves that his attendant something comes out only on bright days and bright nights. It is true, also, that such resemblance as his shadow bears to him, and its approximate separateness from him, are shown only when he stands up: on crouching, it becomes indefinitely formed; and as he lies down it seems to disappear and partially merge into him. But this observation confirms his impression of its reality. This greater or less separateness of his own shadow reminds him of cases where a shadow is quite separate. When watching a fish in the water on a fine day, he sees a dark, fish-shaped patch on the bottom at a considerable distance from the fish, but nevertheless following it hither and thither. Lifting up his eyes, he observes dark patches moving along the mountain-sides—patches which, whether traced or not to the clouds that cast them, are seen to be widely disconnected from objects. These facts show him that shadows, often so closely joined with their objects as to be hardly distinguishable from them, may become distinct and remote.

Thus, by minds beginning to generalize, shadows must be conceived as existences appended to, but capable of separation from, material things. And that they are so conceived is abundantly proved. We find it stated by Bastian of the Benin negroes, that they regard