Bryn Mawr Classical Review 97.12.12

Stephen P. Menn, Plato on God as Nous. Carbondale, IL: Southern Illinois University Press, 1995. The Journal of the History of Philosophy Monograph Series. Pp. xiii, 86. $24.95. ISBN 0-8093-1970-5.

Reviewed by Michael Pakaluk, Department of Philosophy, Clark University,

Word Count: 1,667.

The thesis of this brief and exceedingly elegant book is that Plato, certainly in the late dialogues and probably also in the middle period ones, regarded nous as God and as the ultimate cause of order in the universe. One should not expect to find the doctrine expounded in the middle dialogues, Menn claims, because there Plato's interest is focussed on the intelligible world and how the human intellect can attain to a grasp of it. But in the later dialogues, where his concern evidently turns to accounting for the sensible together with the intelligible world, he needs to introduce nous as the cause of order in the sensible world. The reason for this is that Forms can account only for what it is for each thing to have the features it has: they can no more account for why a thing has the features it has at a certain time, or why it is related to other things that have other features, so that the totality is harmonious and intelligible, than can the mere postulation of a material cause. However, nous, understood as an active causal principle which aims at what is best, does account for these things. An appeal to the Forms, then, gives only a 'second-best' explanation of change in the sensible world; the first-best explanation invokes nous (cp. Phaedo 97c-99c).

Plato's doctrine of nous, according to Menn, is this: (i) nous is best understood, not as Mind, but rather as Reason, "a single substantial unity ... distinct from the world-soul and from all other souls, superior to souls ..." (7); (ii) it is correctly identified with the demiurge of the Timaeus; in fact, the term 'demiurge' signifies merely a relation or role, whereas nous is the very name of this maker; (iii) although nous exists independent of bodies and can act directly upon bodies in the manner of an efficient cause, it prefers to act through 'persuasion' rather than 'coercion' (Timaeus 48a2-5), thus it needs some sort of mediation for its action; and (iv) this mediation is provided by soul, a principle of self-movement, which can participate in nous and have its effects ordered by nous.

Menn maintains (i) against passages of Plato that assert that nous cannot come to be apart from soul (e.g. Phileb. 30a9-10, Euthyd. 287d7-e1, Soph. 239a4-8, Tim. 37a2-4, 46d5-6) by pointing out that Plato should be taken to mean, exactly, that it cannot come-to-be, that is, come to exist and act in the sensible world, without soul, which of course does not imply that it cannot exist in the intelligible world on its own; and Menn accepts R. Hackforth's arguments1 that, in places where Plato seems to deny that nous exists independent of soul, he is speaking, not of nous as creator, but as something in the world, which the world contains by means of soul.

To defend (ii), Menn must of course argue against a view such as F. Cornford's, that the demiurge is simply "the Reason in the World-Soul".2 He does so by pointing out that the World-Soul but not the demiurge is in the class of the gignomena, and that the demiurge imposes limits on the unlimited, which is the action from which soul, too, results. He must likewise, of course, reject H. Cherniss' view that nous is "a personification of the logical abstraction, 'intelligent causation' in general".3 As against this, Menn argues persuasively that otherwise uncoordinated, intelligent causes could not in fact produce an ordered universe, and so the world's order would remain unexplained, if Plato believed what Cherniss attributes to him. Furthermore, we would have to conclude that Plato in fact had no opinion about the first cause of the world, since he simply postulates a plurality of intelligent causes, which could not be taken to be primitive or original. (Menn seems to assume, though he does not argue, that Cornford and Cherniss together cover the more plausible alternatives to his interpretation.)

One of Menn's key arguments for the independence of nous from soul is the consideration that, as he puts it, "the nous that is king of heaven and earth is the virtue of nous" (16). That is to say: when Plato lists nous along with phronesis and episteme as virtues of the souls of particular human beings, as he does in many texts (e.g., Phileb. 13e4, 21d9-10, 28d8; Tim. 34a2; Laws 963a6-9), he is referring to the same thing as that to which he refers, when he calls nous king of the universe. The argument for independence then apparently proceeds: since souls can exist without having the virtues, they can in particular exist without nous; and if nous is like the other virtues, and indeed like other universal terms, then it must have a status for Plato like other universals and exist prior to particulars.

Other support for the idea that Plato regards nous as independent of soul comes from Menn's fascinating discussion of Plato's puzzling claim that his own doctrine of nous is simply what has been held previously by "all the wise" and "those who were before us" (cf. Phileb. 29c6-8). Note that even if we were to grant Socrates pre-eminent authority as a predecessor of Plato, and if we were to accept Memorabilia I.iv.8 as a reflection of the historical Socrates' views, Plato's assertion would still be puzzling. Only Anaxagoras among the pre-Socratics, it seems, mentions nous; and the method of explanation through material cause, common among the early natural philosophers, seems to indicate, precisely, a failure on their part to acknowledge the importance of providing a cause of the order of things, which is the function served by Platonic nous.

Menn would explain Plato's assertion in two stages. He argues, first of all and plausibly, that Plato's doctrine of nous is a development of Anaxagoras' teaching, in the sense that it responds to tensions and difficulties in the latter. Anaxagoras regarded nous as similar to what was indicated by other mass nouns ("water", "earth", etc.). But then it becomes a problem how nous, as distributed among different particular substances, nonetheless acts in a coordinated way, so that the entire world becomes a single ordered whole. Menn sees Anaxagoras' insistence that nous alone is 'unmixed' as an attempt to respond to this problem; but Plato's hypothesis of an independent, controlling demiurge clearly handles the problem better. Again, the manner of action of Anaxagorean nous is difficult to account for. How does nous, as present for instance in a particular human being, bring about order and rationality in that person's actions? Anaxagoras has only one view open to him: nous acts directly upon the body, in the manner of an efficient cause, and by 'coercion' rather than 'persuasion'. (That Anaxagoras was constrained to adopt this view explains, Menn thinks, why Aristotle held that Anaxagoras tended to identify nous and soul: if soul is what is responsible for motion in things, then nous is soul.) But Plato proposes, instead, the view that nous needs something in which to act, viz. a principle of self-movement, or soul, in which case it acts through lending rationality to self-motion, that is, by 'persuasion'.

But once we accept that Plato saw his doctrine of nous as a development of a prominent pre-Socratic view, then we can appreciate that he would wish to assign his view, in a general way, to his forebears. The important consideration here is not that other pre-Socratics used the term 'nous', since they did not. Menn maintains, rather, that we should look to the tendency of the early natural philosophers to identify what they took to be the basic ordering principle of the universe with a virtue or with something virtue-like: for instance, it is Dike and Logos for Heracleitus; Dike similarly for Parmenides; and Philia in Empedocles (on this last point, Menn would have us compare Plato, Gorg. 507e6-508a2). Thus, by insisting that "the nous that is king of heaven and earth is the virtue of nous", Menn can account nicely for Plato's understanding of the provenance of his own cosmological view: Plato was simply continuing the idea the governance of the universe takes place through the action of virtue; but for him the virtue, nous", was also something separate and self-subsistent.

Menn's monograph is a coherent, compact argument, prosecuted in carefully-argued stages, and supported with impressive scholarship in detailed footnotes. He regards this brief book as a necessary prolegomenon to a longer study of Aristotle's Metaphysics, since Menn thinks that that treatise takes the cosmology of the Timeaus as its starting point. We should expect a great gain in insight into that difficult work of Aristotle, if Menn's promised investigation of it is as subtly argued as this, and in the same way based on illuminating philology and exegesis.


1. Reginald Hackforth, "Plato's Theism." In Studies in Plato's Metaphysics, ed. R. E. Allen. London, 1965.  

2. Francis M. Cornford. Plato's Cosmology. London, 1937, p. 187.  

3. Harold Cherniss. Selected Papers. Leiden, 1977, p. 458.