This volume is designed to show the way to the beginner, to satisfy and more especially to excite his initial curiosity. It affords an adequate idea of the march of facts and of ideas. The reader is led, somewhat rapidly, from the remote origins to the most recent efforts of the human mind. It should be a convenient repertory to which the mind may revert in order to see broadly the general opinion of an epoch-and what connected it with those that followed or preceded it. It aims above all at being a frame in which can conveniently be inscribed, in the course of further studies, new conceptions more detailed and more thoroughly examined. It will have fulfilled its design should it incite to research and meditation, and if it prepares for them correctly.