Plotinus’s Aristotelian Road to Plato

The Enneads, the collection of writings by Plotinus, was edited and published by his pupil Porphyry in 270 C.E. In his Preface to the work, Porphyry says that the Enneads is a compendium of Aristotelian thoughts, and its focus is on Aristotle's Metaphysics. He writes: "In style Plotinus is concise, dense with thought, terse, more lavish of ideas than of words, most often expressing himself with a fervid inspiration. He followed his own path rather than that of tradition, but in his writings both the Stoic and Peripatetic doctrines are sunk; Aristotle's Metaphysics, especially, is condensed in them, all but entire."

Lloyd P. Gerson, in his book Plotinus-Arg Philosophers (The Arguments of the Philosophers),  uses Porphyry’s view of the Enneads to make the case that Plotinus, while being devoted to defending Platonism from its opponents, was also close to Aristotle. Gerson notes that the Enneads contain at least 150 direct references to Metaphysics and has references to Aristotle's other works. Here’s an excerpt from Gerson’s Introduction to his book:

"An additional and sometimes overlooked facet of Plotinus’ Platonism is that Plotinus leans heavily on Aristotle for an understanding of what Plato’s doctrines actually were. For one thing, Plotinus’ Plato is sharply distinguished from Socrates, following that perfectly natural distinction in Aristotle. Nothing in the Enneads is derived from or depends on what we have come to recognize as especially Socratic. More importantly, Plotinus follows Aristotle in holding that Plato had an unwritten doctrine of principles. Indeed, Plotinus appears to rely on Aristotle for understanding what that is. Some effort is expended in the Enneads in order to show that this unwritten doctrine is at least consonant with that which appears in the dialogues. Finally Plotinus will frequently accept as authoritative an interpretation of Plato by Aristotle, as interpretation which Aristotle himself thinks leads a Platonic doctrine to shipwreck. Plotinus, however, will typically attempt to show that what Aristotle thinks is a disastrous consequences of a Platonic position is in fact true and even necessary. The alternative Aristotelian position is what ought to be rejected. And yet where Plotinus judges that Aristotle is ready not in disagreement with Plato, he will quietly adopt Aristotle’s terminology, distinctions, and even his explicit conclusions."