We may remark here that on this all the interest of the question for us turns. It would be of very little importance to us, in reality, whether the soul were immortal or not, if the soul of each of us, being really indestructible and immortal, should pass to another than ourselves, or if, reviving in us, it did not possess the memory of our past existence. The resurrection of the soul without the memory of the past would be a real annihilation, this would be the nothingness of the materialists. It must be, then, that the soul lives again after our death, in ourselves, and that this soul, then, has clear remembrance of all the actions which took place in its previous existences. It behoves us, in short, to know, not whether our souls are immortal--that fact is self-evident--but whether they will belong to us in the other life, whether, after our death, we shall have identity, individuality, _personality_. It is to the study of this question that the present work is devoted. We are endeavouring to prove that the soul of the man remains always the same, in spite of its numerous peregrinations, notwithstanding the variety of form of the bodies in which it is successively lodged, when it passes from the animal to the man, from the man to the superhuman being, and from the superhuman being, after other celestial transmigrations, to the spiritualized being who inhabits the sun. We are endeavouring to establish that the soul, notwithstanding all its journeys, in the midst of its incarnations and various metamorphoses, remains always identical with itself, doing nothing more in each metempsychosis, in each metamorphosis of the exterior being, than perfect and purify itself, growing in power and in intellectual grasp. We are endeavouring to prove, that, notwithstanding the shadows of death, our individuality is never destroyed, and that we shall be born again in the heavens, with the same moral personality which was ours here below; in other words, that the human _person_ is imperishable. It is for the reader to say whether we have attained our object, whether we have established the truth of this doctrine conformably with the laws of reasoning and the facts of science. If an absolute demonstration of the existence of an immaterial principle in us be insisted upon, we must reply, that philosophy, like geometry, has its axioms, that is to say, its self-evident truths, which need not, or, if we choose to say so, which cannot be mathematically demonstrated. The existence of the soul is one of those axioms of philosophy. Diogenes answered a rhetorician who denied movement by walking in his presence. By expressing any thought, by saying "yes," or "no," we may prove the existence of the immortal soul to the sophists who would attempt to contest it.