The present work lays out a complete outline of Plotinian doctrine, both as a vision of the world and as a method of spiritual life. The meditation unfolds according to the cyclic or helical scheme of the Neoplatonists. We ascend from the universe, considered as a living whole, then as a system of intelligibles and intelligences, up to the Good which fulfills their unfolding by the exigency which it imparts to them. From this Supreme One we descend again to derivative beings by studying as a matter of course the procession of minds, then that of the soul, and finally the appearance of the sensible. Making our way, we encounter the problems of individuality, of extension, of time and of nature. Everything is thus arranged in order to understand the conversion of souls, which are purified, first from the sensible, then from the intelligible, before reuniting with the unitive presence within themselves.