The Sun and the Good

What place does the Good have in Plato’s ontology? One answer to this question is that the Good is a form just like the other forms and that Plato’s metaphysical account of it does not vary dramatically from the account he gives of the forms in general. Traditionally, however, Platonists have given quite another answer. According to this tradition, the Good occupies a place distinct from the other forms because it is their ontological ground or source and therefore lies beyond both being and intelligibility. In arbitrating between these two views, the analogy of the sun in Republic VI is of central importance. I propose, therefore, to examine this passage closely and determine just how much evidence it yields in favor of each view. I begin by giving a brief overview of the traditional approach, taking Plotinus and Pseudo-Dionysius as representative exponents. I then devote the main body of the essay to a close reading of the passage in question together with some analysis of the philosophical difficulties it posses. Ultimately I conclude that the passage does support the traditional reading, but that this support is not nearly as evident as we may at first suppose and relies on the importation of a logic never made explicit in the text.

Historical Appropriation

In Neoplatonic thought, the ultimate source of reality, the Good or the One, transcends the realm of being and thus lies outside the scope of things which are because it is the ground or source for that realm. Plotinus provides a typical expression of this thought:

In order that Being may be brought about, the source must be no Being but Being’s generator (V.2.1).1

This yields an ontological picture stratified into three levels: (i) the realm of becoming (i.e. spatiotemporal reality), (ii) the realm of being (i.e. the realm of the forms), and (iii) that which is beyond being (i.e. the Good or the One).

The observation that the Good does not belong to the realm of being puts it beyond the possibility of predication also, and thus beyond knowledge. The Good, therefore, also transcends intelligibility because the proper object of intellect is that which is. This strongly negative stance comes out clearly in writers like Pseudo- Dionysius:

Just as corporal form cannot lay hold of the intangible and incorporeal, by the same standard of truth beings are surpassed by the infinity beyond being, intelligences by that oneness which is beyond intelligence. Indeed the inscrutable One is out of the reach of every rational process. Nor can any words come up to the inexpressible Good, this One, this Source of all unity, this supra-existent Being (588B).2

The Good, therefore, is something which can never be properly known or understood by intellect because it is prior to the very conditions of intelligibility. This understanding of the Good has strong affinities with the apophatic traditions of many religions, and because of this, Platonic texts are often appropriated in this context to forward the view that the Good (or God, or the One) is altogether beyond being and knowledge.

Central to the history of this appropriation, Republic VI contains the famous image of the Good as the sun. Ostensibly, we find the direct claim at 509b that the Good is “beyond being,” yet from the immediate context it is not altogether clear what this involves. It may mean, as Plotinus and Pseudo-Dionysius would have it, that the Good is not something which is because it is altogether beyond the realm of being as its ground and cause. It may, however, simply mean that the Good surpasses the form of Being in worth and value but this does not preclude it from belonging, like the other forms, to the realm of things which really are. If this second, deflationary reading is correct, then the Good should also appear as a legitimate object of knowledge. Several of Socrates’s claims in this passage support this reading, yet his claims are often qualified in curious ways. I propose that we look closely at the passage and determine just what we can and cannot infer about the Good from this text alone.

The Sun and Sight

At 508a Socrates lays the groundwork for the allegory of the sun by pointing out the way that the faculty of sight involves three elements:

  1. Objects of sight
  2. Power of sight
  3. Source of sight

Socrates especially calls attention to the addition of this third element by contrasting the faculty of sight with the other faculties. In the case of hearing, for instance, there is no mediating element between a sound and the faculty of hearing. Provided that the faculty of hearing is present and the object of hearing is present, the activity of hearing happens spontaneously. In the case of sight, however, we need both the light which makes the objects visible and the sun “whose light makes our sight see in the finest way and the seen things seen” (508a).3 The sun surpasses light because it is the ultimate “divine source” of sight and being seen. The identification of the sun with the ultimate cause of sight, however, brings about a curious feature of the metaphor as it stands: “though the sun is not itself sight, it is the cause of sight and is seen by the sight it causes” (508b). The sun is now fulfilling not just one, but two of the three roles involved with sight. It alone satisfies (iii) in an ultimate sense, but in terms of (ii) the sun is merely one among the infinite variety of visible objects. The sun may clearly stand out as the brightest of all visible objects, but it does belong to the sphere of visible things.

At first, it may appear that this involves the sun in a viscious form of self causation. After all, how can the sun be both the cause of all visible things and be itself visible? We do not need, however, to say that the sun is the cause of its own existence, merely that it is the cause of itself qua visible thing. Suppose, for instance, that Solon of Athens creates all the laws of Athens and thereby establishes what it means to be a citizen of Athens. In doing so, he does not set himself up as a tyrant, however, but places himself under the laws which he makes. In this sense, Solon is the cause of himself not simpliciter but merely as a citizen. Similarly, the sun is not the source of itself simpliciter, but merely as a visible object.

Socrates goes on to explain at 508c that the sun is that “child of the Good” an account of which he promises to Glaucon at 506e. The sun is its child and is in its “likeness” because it stands in an analogous relationship to three things—and here Socrates makes explicit a fourth element of sight that was only implicit in his earlier description, namely the whole visible realm:

  1. The sun is to sight as the Good is to intellect
  2. The sun is to visible objects as the Good is to intelligible objects
  3. The sun is to the visible realm as the Good is to the intelligible realm.

Socrates places his primary emphasis on this first respect in which the sun and the Good are similar. Just as the sun is the ultimate origin of sight, that in virtue of which all sight is possible, so too the Good is the ultimate origin of all intellect. Further, just as the sun is not identical with sight itself, neither is the Good identical with intellect or any act of intellect, contra those who would claim that the Good is prudence (505b). From what Socrates says, however, it seems that we are also meant to consider the second and third ways in which the sun is related to visibility in the metaphor. In these terms, the sun is just one among many objects which are visible and is therefore within the visible realm like all other visible objects, while also being the source of visibility. From this passage so far, it appears that the Good should be taken as merely one among all those things which are intelligible and therefore within the realm of being.

This interpretation of the metaphor is supported by the description of the Good which Socrates gives at 508e:

Therefore, say that what provides the truth to the things known and gives the power to the one who knows, is the idea of the Good. And, as the cause of the knowledge and truth, you can understand it to be a thing known; but, as fair as these two are —knowledge and truth—if you believe that it is something different from them and still fairer than they, your belief will be right.

The Good, then, is something known and merely surpasses knowledge and truth in fairness rather than ontologically. Socrates, however, inserts cautionary phrases throughout the passage as a whole, and this last description is no exception. What should we make of the phrase “you can understand it to be”? This seems as though Socrates wishes to back off somewhat from the straight- forward assertion that the form of the Good is itself known. Perhaps this description is merely intended as a pedagogical step for Glaucon. On this reading, he would not be wholly wrong to “think of” the Good “as being” something intelligible, but eventually he will need to leave this partial, metaphorical way of thinking behind as he comes to a more adequate understanding. Authors like Plotinus and Pseudo-Dionysius frequently maintain that there are ways of thinking about the Good that are more appropriate than others because they lead the mind toward the recognition that the Good is something ultimately beyond its grasp. Then again, this phrase could be a stronger prescription, and Socrates could be asserting that this is the most appropriate way to think about the Good because this is the way the Good really is. In any case, interpretive caution is called for.

The Sun and Growth

At 509b Socrates asks Glaucon to “pursue our analogy further” and adds another dimension to the metaphor:

I suppose you’ll say the sun not only provides what is seen with the power of being seen, but also with generation, growth, and nourishment although it itself isn’t generation.

This addition is so brief that it is easy to let it slip by unnoticed, but it is striking just how complex the metaphor has become. The sun already stands in relation to three things (sight, visible things, and the visible realm), and Socrates is now adding generation, growth, and nourishment. In parallel, the Good is the source, not only of the intelligibility in things, but also of their “existence” (τὸ εἶναί) and “being” (τὴν οὐσίαν). While he does not state it as explicitly as the other parallels, it seems clear enough that Socrates means to add a forth parallel between the sun and the Good to the three we have already:

  1. The sun is to generation as the Good is to being.

In the metaphor, the sun is the cause of generation wherever it occurs. He is sure to point out that the sun is not identical to generation just as it is not identical to sight, but we may still ask whether the sun is one of those things subject to the process of generation. In the terms of the metaphor, there did not seem to be any internal difficulty in claiming that the sun is both the source of sight and also something which is seen. The sun, in this case, is a causa sui in a weak, non-vicious sense because it is only the cause of itself qua visible object. In the case of generation, however, a stronger self-causation threatens. If the sun is the ultimate source of the process of generation then it will be a necessary precondition for every instance of it. The sun would need to be already in order to cause its own process of coming to be. Although Socrates remains silent on this point, the logic of the metaphor seems to indicate that the sun lies outside the realm of coming to be in a way that it did not lie outside the realm of sight.

It is at this point that we find the famous claim that the Good is “beyond being,” but we must be sure to read to the end of the sentence:

Therefore, say that not only being known is present in the things known as a consequence of the Good, but also existence [τὸ εἶναί] and being [τὴν οὐσίαν] are in them besides as a result of it, although the Good isn’t being [οὐκ οὐσίας ὄντος τοῦ ἀγαθοῦ] but is still beyond being [ἔτι ἐπέκεινα τῆς οὐσίας], exceeding it in dignity and power. (509b)

According to the traditional reading, this passage claims that the generation of visible objects is analogous to the “being and reality” of the objects of intellect, i.e. the Forms, so that the Good is somehow beyond this being and reality because it is the source of it. In the metaphor, the sun is neither something that comes to be nor the process of generation, but the source of both. Given this analogy, we may think that the Good is not itself a being because it is the source of being. The Good then is beyond being in the sense that it is outside of its scope, transcending the realm of being altogether as its antecedent ground and source.

According to the deflationary reading, when he claims that the Good is not being, Socrates may be making the much less radical claim that the Good is merely non-identical with the form of Being itself. That is to say he is merely calling attention to the way that they are two distinct forms. This reading is somewhat supported if we understand the phrase “surpassing it in dignity and power” to be a qualification of the claim that the Good is “beyond being” rather than a separate claim in its own right. If this reading is right, the Good is not beyond being simpliciter but merely beyond it in dignity and power.

The observations that the Good is non-identical with being and greater than being in dignity and power are, on their own, compatible with the conclusion that the Good is nevertheless one of those things which are, and therefore is subject to the form of Being in that sense. On this reading, this passage about the relationship between the Good and being is highly parallel to the earlier passage about its relationship to knowledge. Just as the Good is something distinct from knowledge and “more splendid” than it, the Good is distinct from being and “surpasses it in dignity and power.” Nevertheless, just as the Good is something known, there is no reason to suspect that it is not something which is. We should remember, however, our earlier caution that this may be merely the “right way to think about” the Good rather than the plain truth. If we are to overturn this deflationary reading we must bring into consideration the logic of what it means for something to be the “source” of being, a logic which is never drawn out explicitly in the text.


The famous description of the Good as “beyond being” at 509b in the analogy of the sun does not immediately or obviously imply a strong ontological transcendence of the Good. It is tempting to cite this passage in discussions of Neoplatonism as though it were a clear statement of Plato’s position, yet there are several indications in the surrounding text that the Good is something that can be known, and therefore belongs to the realm of things which are. Nevertheless, the fact that this account is merely an allegory and only proposes to tell the tale of the “child of the Good” taken together with the curious qualifications Socrates attaches to his claims that the Good can be known give us some interpretive leeway. Ultimately, the logic of viscous ontological self-causation justifies the appropriation of this text within Neoplatonism, but we must be sure to understand that Socrates never brings this logic into the discussion here. When we add this logic, the passage appears in a Neoplatonic light, but if we remove it, the claims of this passage appear much less radical.

  1. Plotinus, Enneads, trans. Stephen MacKenna (Larson Publications, 1992).↩︎

  2. Pseudo-Dionysius, Complete Works, trans. Colm Luibheid (Paulist Press, 1987).↩︎

  3. All translations taken from Plato, The Republic, trans. Allan Bloom (Basic Books, 1991).↩︎

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