Was Neoplatonism a synthesis of Jewish & Platonic monotheism?

Question

Was Neoplatonism a synthesis of Jewish & Platonic monotheism?

Neoplatonism was a school of mystical philosophy synthesising Jewish theology and Plato's philosophy. Its major theorist & practitioner is Plotinus.

But there appears to be two dialogues of Plato in which such a philosophy could be drawn from - that is Parmenides and Timaeus.

Obviously monotheism is not usually associated with Plato. But consider that Parmenides is a discussion on the intrinsic nature of the One; and that in Timaeus he discusses how the Grand Artificer/Craftsman created the world. There is no indication that these are the same; but he expects the creation story to be taken seriously in some manner if the following passage is any indication:

Timaeus: If then, Socrates, amid the many opinions about the gods and the generation of the universe, we are not able to give notions which are altogether and in every respect exact and consistent with one another, do not be surprised. Enough, if we adduce probabilities as likely as any others; for we must remember that I who am the speaker, and you who are the judges, are only mortal men, and we ought to accept the tale which is probable and enquire no further.

Is it this monotheism the point of contact by which Plotinus was able to weld the two traditions together?

Answer 1

This is only a partial answer presenting some doubts that Plotinus was attempting a synthesis of Jewish and Platonist traditions of monotheism.

Plotinus’s monotheism would come from the introduction of the One through what Dominic J. O’Meara calls the "Principle of Prior Simplicity", that is, “the idea that everything made up of parts, every composite thing, depends and derives in some way from what is not composite, what is simple.” (Plotinus: An Introduction to the Enneads, Oxford, 1995, p. 44) This principle is also called the doctrine of divine simplicity.

Further according to O'Meara (p. 44-5):

Applying the Principle of Prior Simplicity, Plotinus thus came to the conclusion that we must postulate, over and beyond divine intellect, an ultimate cause which would be absolutely simple, the 'One'. In drawing this conclusion Plotinus not only separated himself from his Platonist and Aristotelian predecessors; he also believed himself to be in a position to throw light on some crucial but obscure passages in Plato's dialogues.

From O'Meara's perspective it seems that Plotinus was mainly interested in expounding Plato, not assimilating Jewish traditions into Platonism.

William Wainwright in his “Monotheism” SEP article listed divine simplicity as only one argument for monotheism. Other ways to argue for monotheism would be through God’s perfection, sovereignty, omnipotence and demand for total devotion. Also Wainwright claims that “not all theists accept” divine simplicity. The idea of divine simplicity may not have had an adequate influence to form a synthesis of Jewish and Platonist views of monotheism.

There is also the controversial Tübingen School maintaining that Plato had unwritten doctrines containing much of what is believed to be new in Plotinus. If Plotinus did not offer much that was new his role in welding the two traditions, Jewish and Platonist, might be minor.

According to the cited Wikipedia article:

Neoplatonism had an enduring influence on the subsequent history of philosophy. In the Middle Ages, Neoplatonic ideas were studied and discussed by Islamic, Christian, and Jewish thinkers.

Whatever happened after Plotinus, a synthesis of Jewish and Platonist ideas about monotheism may not have been his motivation.

Answer 2

Plotinus' relation to Plato seems straightforward but is not. But that he has some relation to Plato, that he treats Plato frequently as a touchstone, is clear. Jewish influence on Plotinus' thought, via Philo, is a possibility for which I can only give references.

Plotinus and Plato

E.R. Dodds sets out the seemingly straightforward relation as follows :

It is natural to begin by asking what Plotinus thought of his own work and how he conceived his historical function. To this the answer is easy, but disappointing. Plotinus apparently did not know that he was a Neoplatonist; he thinks of himself as a Platonist tout court. ' These doctrines,' he says (5, 1, 8, 10), speaking of his own system, 'are no novelties, no inventions of to-day; they were stated, though not elaborated, long ago; our present teaching is simply an exposition of them-we can prove the antiquity of these opinions by Plato's own testimony.' This is not the language of a creative thinker acknow- ledging his debt to a great predecessor ; it is the language of a schoolman defending himself against a charge of unorthodoxy ... And indeed Plotinus avoids as a rule making any claim to originality; the rare exceptions have reference only to details of his system. (E.R. Dodds, 'Tradition and Personal Achievement in the Philosophy of Plotinus', The Journal of Roman Studies, Vol. 50, Parts 1 and 2 (1960), pp. 1-7 : 1.)

Dodds next proceeds to look past first appearances - the 'easy answer' - and to vindicate Plotinus' originality :

Formally, but only formally, the philosophy of Plotinus is an interpretation of Plato; substantially, I should call it an attempt to solve the spiritual problems of his own day in terms of traditional Greek rationalism. He nowhere openly disagrees with his Master, though he recognizes that Plato sometimes speaks in riddles (6, 2, 22), leaving us to work out his meaning for ourselves (5, 8, 4), and also that his teaching is not always consistent, at any rate on the surface (4, 4, 22 ; 4, 8, 1). For each of the major features of his own system he can produce, and feels obliged to produce, certain Platonic texts as 'authority' ...

But these Platonic texts are not the true starting-points of his philosophy: he does not believe in the One because he has found it in the Parmenides; on the contrary, he finds it in the Parmenides because he already believes in it. Nor does his exposition normally start from Plato: his more usual method is to state a problem and try out various ways of solving it until he arrives at something which he finds logically satisfying; then, and most often only then, he will cite for confirmation a text from Plato. In fact, he quotes Plato pretty much in the same spirit in which some seventeenth-century philosophers quote Scripture-not as part of his logical argument but as evidence of orthodoxy. His basic question is not the historical one, ' What did Plato think about this ? ' but the philosophical one, ' What is the truth about this ? ' Respect for the Great Founder required, indeed, that both questions should have the same answer. But where violence had to be used to achieve this agreement it is generally Plato who is wrenched into concordance with the truth; so far as I can judge, the truth is seldom distorted to make it agree with Plato. Had Plato never lived, Plotinus would have had to formulate his thought in some entirely different way, but I am tempted to guess that its general structure and direction would still have been recognizably what they are. What spoke to him in Plato's name was his own daemon, even when it used the very words of Plato. (Dodds, 1,2.)

Dodds recognises that 'Stoic and Peripatetic elements are to be found in his [Plotinus'] writings' (Dodds, 2) but what of Plotinus's possible indebtedness to Jewish thought ?

Plotinus and Philo

Both McGinn and Idel have noted the importance of mystical union in Philo’s thought and its possible influence on the articulated discussions of unio mystica in Plotinus and consequently on the entire Western mystical tradition ... Bernard McGinn, “Love, Knowledge, and Mystical Union in Western Christianity: Twelfth to Sixteenth Centuries,” Church History 56 (1987): 7–24, and “Love, Knowledge and Unio Mystica in the Western Christian Tradition,” in Idel and McGinn, Mystical Union in Judaism, Christianity and Islam, 59–86. (Adam Afterman, 'From Philo to Plotinus: The Emergence of Mystical Union', The Journal of Religion, Vol. 93, No. 2 (April 2013), pp. 177-196 : 178.)