This vast panorama of fundamental philosophical questions, which the author initiated with Leçons platoniciennes (1997) and pursued in Leçons aristotéliciennes (2002), and which has never deviated from the stoic trinity (metaphysic/logic/ethics), comes full circle today with the publication of Leçons plotiniennes. The work of Plotinus - the true founder of the Platonic tradition of exegesis known as "Neo-Platonism " dominated Greek-language philosophical life until early in the 6th century - contributed an unprecedented dimension to this long tradition of commentary. By drawing from Plato's Parmenides (rather than from Timaeus), the Enneads - the culmination of all Greek wisdom and Aristotelianism and pagan religious thought - constitute a rational exposition of all reality in fifty-four treatises. The " One " is the Operating Principle, Founder and Absolute Being, from which emanates all of the world's reality.Formerly a professor at Université de Caen and at the Université de Genève, Alexis Philonenko is now a Professor Emeritus at Université de Rouen. He has published numerous works which have earned him his reputation as one of the most important philosophic thinkers of our time.