All the different classes of beings which taken together make up the universe are, in the ideas of God who knows distinctly their essential gradations, only so many ordinates of a single curve so closely united that it would be impossible to place others between any two of them, since that would imply disorder and imperfection. Thus men are linked with the animals, these with the plants and these with the fossils which in turn merge with those bodies which our senses and our imagination represent to us as absolutely inanimate.
Gottfried LeibnizThere is no argument so cogent not only in demonstrating, the indestructibility of the soul, but also in showing that it always preserves in its nature traces of all its preceding states with a practical remembrance which can always be aroused. Since it has the consciousness of or knows in itself what each one calls his me. This renders it open to moral qualities, to chastisement and to recompense even after this life, for immortality without remembrance would be of no value.
Gottfried Leibniz