Another objection will be made to our doctrine. It will be said: The re-incarnation of souls is not a new idea; it is, on the contrary, an idea as old as humanity itself. It is the metempsychosis, which from the Indians passed to the Egyptians, from the Egyptians to the Greeks, and which was afterwards professed by the Druids. The metempsychosis is, in fact, the most ancient of philosophical conceptions; it is the first theory imagined by men, in order to explain the origin and the destiny of our race. We do not recognize an argument against our system of nature in this remark, but rather indeed a confirmation of it. An idea does not pass down from age to age, and find acceptance during five or six centuries, by the picked men of successive generations, unless it rests upon some serious foundation. We are not called upon to defend ourselves because our opinions harmonize with the philosophical ideas which date from the most distant time in the history of the peoples. The first observers, and the oriental philosophers in particular, who are the most ancient thinkers of all whose writings we possess, had not, like us, their minds warped, prejudiced, turned aside by routine, or trammelled by the words of teachers. They were placed very close to nature, and they beheld its realities, without any preconceived ideas, derived from education in particular schools. We cannot, therefore, but applaud ourselves when we find that the logical deduction of our ideas has led us back to the antique conception of Indian wisdom. There is, however, a profound difference between our system of the plurality of lives, and the oriental dogma of the metempsychosis. The Indian philosophers, the Egyptians, and the Greeks, who inherited the maxims of Pythagoras, admitted that the soul, on leaving a human body, enters into that of an animal, to undergo punishment. We entirely reject this useless step backward. Our metempsychosis is upward and onward, it never steps down, or back. A brief sketch of the dogma of the animal metempsychosis, such as it was professed by the different philosophical sects of antiquity will not be out of place here. We shall explain in what particulars the oriental dogma differs from our system, and show, at the same time, how popular the metempsychosis was among the peoples of antiquity, in Europe as well as in Asia.