It would be difficult to find any intelligent person in this age of the world who has not some theory or opinion in regard to the origin of man, and perhaps almost as difficult to find any such person who can give a good and sufficient reason for the faith that is in him. This is especially the case with those who look upon man as a product of evolution, a natural outgrowth from the world of lower life, since here simple faith or ancient authority is not sufficient, as in the creation hypothesis, but scientific evidence and logical argument are necessary. It is to enable this class of readers to test the quality and sufficiency of their belief that this book has been prepared.