At this point the materialist interposes with an argument which he regards as crushing. He reminds us that if we would estimate the value of an idea, as of a race-horse or a mastiff, it is well to take a look at its pedigree. What, then, is to be said--he scornfully asks--of a doctrine of personal immortality which when reduced to its lowest terms is seen to have started in a savage's misinterpretation of his dreams? What more is needed to prove it unworthy of the serious attention of a scientific student of nature? On the other hand, the student whose mood is truly scientific will feel that one of mankind's cardinal beliefs must not be dismissed too lightly because of the crudeness and error in that primitive stratum of human thought in which it first took root. In his perceptions within certain limits the savage is eminently keen and accurate, but when it comes to intellectual judgments that go at all below the surface of things his mind is a mere farrago of grotesque fancies, wherein, nevertheless, some kernels of truth are here and there embedded. It is a long way from the dragon swallowing the sun to the interposition of the moon's dark body between us and that luminary. The dragon was a figment of fancy, but the eclipse was none the less a fact. Now if we may take an illustration from the workings of an infant's mind, it is pretty clearly made out that as baby sits propped among his pillows and turns his eyes hither and thither in following his mother's movements to and fro in the room, she seems in coming toward him to enlarge and in going away to diminish in size, like Alice in Wonderland. It is only with the education of the eye and the small muscles which adjust it that the larger area subtended on the retina instantly means comparative nearness and the smaller area comparative remoteness. At first the sensations are interpreted directly, and the impression upon baby's nascent intelligence is a gross error. The mother is not waxing great and small by turns, but only approaching and receding. If, however, we consider that in baby's mind the enlarged retinal spot means more and the diminished spot less of the pleasurable feelings excited by a familiar and gracious presence, the approach of which is greeted with smiles and out-stretched arms, while its departure is bemoaned with cries and tears, we see that as to the essentials of the situation the dawning intelligence is entirely right, although its specific interpretation is quite wrong. Mamma has not really dwindled and vanished like the penny in a conjurer's palm, but has only flitted from the field of vision.