Lloyd P. Gerson 
Plotinus-Arg Philosophers [PDF ebook] 

First published in 1999. We are fortunate in possessing a fascinating document, The Life of Plotinus, written by the philosopher Porphyry, a pupil and associate of Plotinus for the last eight years of his life. The basic facts contained in this Life can be quickly recounted. Plotinus was likely a Greek born in Egypt in AD 205. It is possible, though, that he came from a Hellenized Egyptian or Roman family. In his 28th year, Plotinus discovered in himself a thirst for philosophy. This is a collection of his works- Ennead I contains treatises on what Porphyry calls "ethical matters"; Enneads II-III contain treatises on natural philosophy or cosmology, with some rationalizations for the inclusion of III. 4, 5, 7, and 8. Ennead IV concerns the soul; V Intellect or and VI being, numbers, and the One. The thematic unity of Enneads I, IV, and V is somewhat greater than the rest.