This third volume concludes the project of offering in an independent and unitary way a complete set of Gnostic writings that are not part of the Nag Hammadi library. Along with the news on the so-called "libertine gnostics" transmitted by Clement of Alexandria and Epiphanius of Salamis, the sources of Gnostic hermeticism are given here in the Corpus Hermeticum, Jamblicus of Chalcis and Zosimus of Panopolis, and the testimonies of Different Neoplatonic philosophers, such as Plotinus, Porphyry, and Proclus. The texts assembled here allow to complete the rich fresco of Gnosticism of late Antiquity and attest to the importance of the current of Christian Gnosticism which, without dissociating philosophical theory and practice, is placed halfway between the Pythagorean Platonists and Orthodox Christians, not Forming part of neither of these two groups.