Plotinus (204/5-270 CE) was the first and greatest of Neoplatonic philosophers. His writings were edited by his disciple Porphyry, who published them many years after his master's death in six sets of nine treatises each (the Enneads).
Plotinus regarded Plato as his master, and his own philosophy is a profoundly original development of the Platonism of the first two centuries of the Christian era and the closely related thought of the Neopythagoreans, with some influences from Aristotle and his followers and the Stoics, whose writings he knew well but used critically. He is a unique combination of mystic and Hellenic rationalist. His thought dominated later Greek philosophy and influenced both Christians and Moslems, and is still alive today because of its union of rationality and intense religious experience.
In his acclaimed edition of Plotinus, Armstrong provides excellent introductions to each treatise. His invaluable notes explain obscure passages and give reference to parallels in Plotinus and others.
Egyptian-born Roman philosopher Plotinus and his successors in the 3rd century at Alexandria founded and developed Neoplatonism, a philosophical system, which, based on Platonism with elements of mysticism and some Judaic and Christian concepts, posits a single source from which all existence emanates and with which one mystically can unite an individual soul; The Enneads collects his writings.
Saint Thomas Aquinas combined elements of this system and other philosophy within a context of Christian thought.
People widely consider this major of the ancient world alongside Ammonius Saccas, his teacher. He influenced in late antiquity. Much of our biographical information about Plotinus comes from preface of Porphyry to his edition. His metaphysical writings inspired centuries of pagan, Islamic, and Gnostic metaphysicians and mystics.