The Secret Doctrine and the Gigantomachia: Interpreting Plato’s Theaetetus-Sophist

The Theaetetus’ ‘secret doctrine’ and the Sophist’s ‘battle between gods and giants’ have long fascinated Plato scholars. I show that the passages systematically parallel one another. Each presents two substantive positions that are advanced on behalf of two separate parties, related to one another by their comparative sophistication or refinement. Further, those parties and their respective positions are characterized in substantially similar terms. On the basis of these sustained parallels, I argue that the two passages should be read together, with each informing and constraining an interpretation of

Plato, as is well known, presents the Sophist as a literary companion to the Theaetetus. Most conspicuously, the Sophist's first line-Theodorus: 'We've come at the proper time by yesterday's agreement, Socrates' (216a1)-directly answers the last lines of the Theaetetus-Socrates: 'let us meet here again in the morning, Theodorus' (210d3-4). 1 In this way and others, Plato rhetorically flags the Sophist as a continuation of the recorded conversation begun at Theaetetus 143d1.
The Sophist does not merely pick up where the Theaetetus leaves off, however. The two dialogues are more intimately connected. In what is perhaps the most famous example, the Sophist fills out the Theaetetus' discussion of false judgment. Rather than simply branching out in new directions, the Sophist, at least on occasion, is informed by, returns to, and supplements substantive discussions in the Theaetetus.
In what follows, I aim to highlight another such point of contact between the two dialogues. Specifically, I will present three comprehensively developed parallels between, on the one hand, the Theaetetus' discussion of the flux theorists and their 'secret doctrine' and, on the other hand, the Sophist's discussion of the giants in their fight against the 'friends of forms.' I will show that [1] both passages exhibit the same basic structure, in which two substantive positions are presented on behalf of two separate parties, related to one another by their comparative sophistication or refinement, and that [2] those parties and [3] their respective positions are characterized in remarkably similar terms (see Figure 1).

The Secret Doctrine and the Gigantomachia:
Interpreting Plato's Theaetetus-Sophist Elements of these parallels have been observed previously, but they are almost always mentioned only in passing, typically consigned to footnotes. 2 By focusing on them directly and considering them as a group, I aim to support a pair of related methodological theses. In particular, I submit, Plato's efforts to wed these sections of the Theaetetus and Sophist suggest that an interpretation of the relevant part of either dialogue both can inform and should complement an interpretation of the other. If correct, we will have a trove of fresh resources, from Plato himself no less, to guide our interpretations of two of the most notoriously challenging passages in the corpus.
Let me begin with the relevant section of the Sophist (246a-249d). The Eleatic Visitor there presents 'something like a battle between gods and giants […] over being ' (246a4-5). 3 The battleground is ontology. Each party aims to advance a 'detailed account […] of that which is' (245e6).
From this introduction, one might expect those on either side of the field to uniformly hold a single view. But this is not the case. At any rate, the giants, on whom I will focus, 4 are hardly a monolithic group. They split into two factions. At the outset of the battle, we meet the first-the 'crude giants,' as I will call them. They 'insist that only what offers tangible contact is, since they define being as the same as body' (246a10-b1). Their initial foray, then, consists in offering a view about both the intension and the extension of being. What it is to be, on the crude giants' account, is to be a body. Accordingly, all and only bodies-those things affording tangible contact-are. 5 That identification of being and body leaves the crude giants immediately vulnerable to attack and prefigures the introduction of a second faction to take up their standard. The trouble for the crude giants begins with the extensional component of their thesis. Some of the things that respectable Greeks would count among beings do not seem to be bodies. 6 Of special note are souls and the virtues.
Since the crude giants are said to be difficult-'perhaps just about impossible' (246d1)to talk to, we cannot be certain whether they would [i] admit souls and virtues as genuine exceptions and so challenges to their thesis, [ii] bite the bullet and preclude them from their ontology, or like the Stoics after them, 7 [iii] take both souls and virtues to be bodies and so unproblematic. The Visitor suggests that the crude giants, hardened in their ways, would deflect the question, stubbornly reasserting their thesis and failing to engage (247c4-5). When challenged, they just 'won't listen […] any more' (246b3).
In the crude giants' stead, the Visitor thus questions some imagined 'better people' (246d7 and e2), whom I will call 'refined giants.' The refined giants are partial to the view of their crude compatriots but ultimately concede defeat on that front. 'The soul seems to them to have a kind of body,' making it, if not a body, at least bodily and so providing a small measure of solace; 'but as far as [the virtues] are concerned, they're ashamed and don't dare either to agree that they are not beings or to insist that they are all bodies' (247b8-c2). Since the refined giants will neither dismiss souls and the virtues as nonbeings nor accept them as bodies, options [ii] and [iii] are off the table. This leaves only option [i] remaining. With the soul and the virtues in mind, the refined giants retreat from the crude position that everything is a body and, with it, from the position that being and body are the same.
To retrench, the Visitor claims, they have to reflect upon the various kinds of beings that they recognize-namely, bodies and now souls and the virtues as well-and determine what is common among them that might qualify them all as beings (247d2-4). 8 Since the refined giants are not present to speak for themselves, Theaetetus and the Visitor suggest a new, more fortified position on their behalf. The refined giants are thus agreed to advance the view that 'a thing really is if it has any capacity at all, either by nature to do something to something else or to have even the smallest thing done to it by even the most trivial thing;' they 'take it as a definition 9 that those which are amount to nothing other than capacity' (247d8-e4; cf. 248c4-5).
This new position, as one commentator puts it, 'is not a complete abandonment' of the crude giants but rather 'an attempt to articulate the spirit of their original position, in a way that accommodates the Visitor's counterargument.' 10 Its emphasis on capacity (dunamis) is distilled from the introduction of bodies as whatever is causally salient. For the crude giants, the noteworthy mark of a body was that it afforded tangible contact (246a10). 11 Bodies, that is, were first presented as having a particular kind of capacity for action or passion. The refined giants thus home in on the only feature of bodies that the crude giants had singled out for attention and present it in its pure, unadulterated form. That is, the refined giants are not merely possessed of a better, or more refined, character than their crude compatriots; their position refines that of their crude compatriots as well. And that latter refinement is of no small significance. It allows the refined giants to treat souls and the virtues alongside bodies, 12 thus disarming the Visitor's challenge.
With that survey of the giants' tours of duty complete, I turn now to the Theaetetus' fluxists and begin to draw parallels between the two. The fluxists make their entrance in connection with Theaetetus' proposal that 'knowledge is simply perception' (151e2-3). Socrates will disabuse him of that view, but the path forward is long and largely indirect. For the most part, Socrates' objections are leveled at one of two theses that Theaetetus' proposed definition of knowledge is purported to imply: 13 the familiar, Protagorean dictum that 'man is the measure of all things' (152a2-3) and a much less familiar, 'secret doctrine' (152c10) held by some 'fluent fellows' (181a4), who are commonly referred to in the secondary literature as 'flux theorists,' or 'fluxists.' 14 Initially, it seems as if the fluxists are most concerned to advance a theory of perception and some related theses in the philosophy of language. But as it turns out, these are derivative parts of their doctrine. At its core, Socrates claims, the secret doctrine presents an ontology. As he puts it, their various claims about perception and language 'begin from the principle [archê] that everything is really motion and there is nothing besides motion' (156a3-5).
I discuss that principle below. What is important to observe at the outset is that just as the Sophist presented two factions of giants, so, too, the Theaetetus presents two factions of fluxists. Before introducing the heart of the secret doctrine, Socrates issues a warning. We must take care, he says, that 'none of the uninitiated are listening' (155e3). What can one say about this latter group? To begin, they are obviously not party to the content of the secret doctrine, for otherwise there would be no reason to avoid expressing it in their presence. Nonetheless, they cannot simply be identified with those who have not yet come to know the secret doctrine, for otherwise Theaetetus would count among their ranks, and Socrates would not go on to present it to him. 15 Instead, they are broadly in league with those already initiated, but they stand, as of yet, separated off; much like fraternity pledges, they are candidates for being brought into the fold.
Further, the uninitiated are distinguished from their initiated compatriots by their comparative lack of refinement. They are said to be 'very crude people [amousoi]' (Theait. 156a2) relative to the 'much more refined [polu komp-soteroi]' initiates (156a2). 16 That is, the uninitiated are the crude counterparts to a faction of more refined fluxists, standing to them just as the crude giants stood in relation to their more civilized and sophisticated compatriots (Soph. 246c9, d7, and e2). 17 The crude giants are further characterized in two ways that even more powerfully liken them to the Sophist's crude giants. First, Plato describes them in corporeal terms, associating them with the earth especially. They are 'hard to the touch [sklêros]' and 'resistant [antitupous]' (Theait. 155e7-156a1), 18 making them firm examples of bodies, as the crude giants describe them, which 'offer tangible contact' (Soph. 246a10). 19 The nature of their development is even more telling. We learn that 'There are no pupils and teachers among these people. They just spring up on their own [automatoi anaphusontai]' (Theait. 180b9-c1). That final expression models their genesis on that of plants, growing of themselves from the earth. This finds an analogue in the Visitor's description of the crude giants as 'earth people [gêgeneis]' (Soph. 248c1), 'grown from seed [spartoi]' and 'sprung from the land itself [autochthones]' (247c5). 20 And second, much as the crude giants are 'just about impossible' to converse with (Soph. 246d1), one cannot have a philosophical discussion with a crude fluxist 'any more than [one] could with a maniac' (Theait. 179e5-6). The trouble, as in the case of the crude giants, who could not be compelled to 'answer less wildly' (Soph. 246d6), is that the crude fluxists are restless. As Theodorus' puts it: 'As for abiding by what is said, or sticking to a question, or quietly answering and asking questions in turn, there is less than nothing 21 of that in their capacity' (Theait. 179e7-180a2). 22 The crude fluxists resemble the crude giants not only in description but also in doctrine. Their insistence that 'nothing exists but what they can grasp with both hands' (Theait. 155e4-5) very nicely tracks the crude giants' insistence 'that only what offers tangible contact is' (Soph. 246a10-b1). 23 Indeed, their view is even more forcefully recalled by a later summation of the crude giants' position: namely, that 'anything they can't squeeze in their hands is absolutely nothing' (Soph. 247c5-7). 24 These giants thus approach the battlefield 'clutching rocks and trees with their hands' (246a8-9)-that is, clinging to the tangible bodies on the ground, in contrast to the invisible beings that the friends of forms, their foes, champion from more ethereal climes.
These parallels cannot but be deliberate on Plato's part. The crude fluxists and the crude giants are presented as being one and the same, as are their positions. Since we have seen that each of these crude factions is compared to a more refined one, we should expect to find further parallels in Plato's presentations of their more refined compatriots and their more refined positions. The texts push, albeit less forcefully, precisely in that direction.
Apart from their relative refinement, which should be regarded as an initial parallel, neither the nobler fluxists nor giants are particularly well described. There is accordingly little to compare across Plato's characterizations of each. That absence of characterization, however, should itself be regarded as a further parallel in Plato's presentation, for its explanation is in each case the same: namely, both camps are ultimately presented as being fictional. 25 Because the Theaetetus' crude fluxists are not capable of conversation, Socrates, Theaetetus, and Theodorus agree to 'come to the rescue' (164e6) and 'take their doctrine out of their hands and consider it for ourselves' (180c5-6). Whether someone actually holds the doctrine in question is incidental to the discussion. As a result, the refined fluxists are not so much advocates of a position as they are placeholders for anyone who might (be tempted to) advance it. 26 Similarly, in the Sophist, Theaetetus and the Visitor agree to deal with the crude giants' intransigency 'by making them actually better than they are […] in words' (246d4-5). As a consequence, the focus must again be more on the position than on those who hold it. As the Visitor says, 'we're not concerned with the people; we're looking for what's true' (246d8-9).
What, then, can we say about the ways in which their respective doctrines are presented? At first glance, frankly, they would appear to be at odds. That of the refined giants is framed in terms of capacity (dunamis). Their central tenet, to recall, is that 'those which are amount to nothing other than capacity' (Soph. 247e3-4). That of the refined fluxists, by contrast, is framed in terms of motion (kinêsis). Their central tenet is that 'everything is really motion and there is nothing besides motion' (Theait. 156a3-5).
There are, nevertheless, two principle classes of parallels that serve to largely bridge that difference in framing and more broadly align the two doctrines. 27 The first class bears directly on their central claims. To begin, we may note, both are ontological. Both, further, appeal to a single criterion (capacity; motion). 28 And in each case, that criterion is similarly dichotomous. For the refined giants, there are two basic kinds of capacities, those for action and those for passion (Soph. 247e1, 248c5 and 7). Likewise, for the refined fluxists, 'there are two kinds of motion, […] the one having the capacity to act and the other the capacity to be acted upon' (Theait. 156a5-7, trans. after McDowell).
Their central claims are thus related not only in structure but also in content, as both use capacities for action and passion to ground their respective doctrines. 29 This parallel is strengthened by a common conception of actions and passions and, thus, of the capacities for them. First, both assume that actions and passions just are motions. In light of their treatment of the two kinds of motion, I take it that this is obvious for the refined fluxists. 30 But one also finds the assumption operative in the Sophist, where those in the grips of the refined giants' doctrine find it inevitable that, for example, if being known is a passion, 'then insofar as [a thing] is known, it's moved [kineisthai]' (248e3-4). 31 Accordingly, both parties assume that capacities, generally, are capacities for motion. 32 Second, both assume that actions and passions are systematically interrelated. In particular, for every action there is a distinct, complementary and reciprocal passion, and vice versa. The refined fluxists thus speak of their 'twin births' (Theait. 156b1), and the refined giants assume, for example, that 'if knowing is doing something, then necessarily [anagkaion] what is known has something done to it' (Soph. 248d10-e1). Accordingly, both assume that the capacities for those actions and passions are analogously paired. 33 A second, indirect class of parallels obtains between the corollaries drawn, in each dialogue, from those central ontological claims. Before addressing them, however, a preliminary point is in order. In the Sophist, those corollaries are revealed in the Visitor's treatment of the giants' opponents, the friends of forms, who initially accept a qualified version of the refined giants' capacity doctrine. At this point in the exchange, the friends of forms alter the capacity doctrine only by qualifying its scope. The doctrine applies in full, they allege, to everything that the refined giants recognize in the ontology (that is, as the friends of forms would put it, to the entire domain of coming-to-be); yet there is also, on their view, a more exalted domain of imperceptible, non-bodily forms to which the capacity doctrine does not apply (248c1-9). The friends of forms are thus a valuable source for the refined giants' capacity doctrine.
Two points in that discussion are especially striking. First, insofar as they hold the capacity doctrine, the friends of forms are said to 'break [bodies] up into little bits and call each a process of coming-to-be instead of being' (Soph. 246b9-c2). This cannot but recall the refined fluxists' claim that each body is an 'aggregate [hathroismati]' of 'becomings' that resist description in terms of 'the verb "to be"' (Theait. 157b1-c3; cf. 152d7-e1). Second, and even more notably, the friends of forms take perception to be the analogue of knowledge in the domain of coming-to-be (Soph. 248a10-11). Since, again, this is only domain that the refined giants admit, the implication is that knowledge is no mere analogue of perception for the refined giants; it just is perception. That is to say, the refined giants are presented as being committed to the single most dialectically significant corollary of the refined fluxists' position-namely, the claim that 'knowledge is simply perception' (Theait. 151e2-3). 34 All told, I submit, we thus have considerable evidence for strongly associating the refined fluxists with the refined giants and for strongly associating their respective positions.
If, as these parallels suggest, the Theaetetus' fluxists and the Sophist's giants are, at the very least, philosophical kin, then our interpretative approach to these dialogues should be dramatically altered. On the one hand, we are licensed to draw upon, and would do well consult, the relevant section of one dialogue to inform and advance an interpretation of that of the other. On the other hand, we are at the same time constrained, in that an interpretation of the one should not, on the whole, fail to broadly compliment an interpretation of the other. In each respect, standard interpretations of the Theaetetus-Sophist will require revision and supplementation. My hope is that we are now better poised to determine the form that those emendations should take. 35  Centrone 2008, n. 106 and 107, Cornford 1935, 48 n. 2, Karfík 2011, 124 and 131, Klein 1977, 89, Notomi 1999, 217 n. 21, Polansky 1992, 96, Ross 1953, 102-103, Sedley 2004, 46 n. 9, Seeck 2011, 74 n. 62, Špinka 2011, 232, Teisserenc 2012, 74, 76, and 78, Waterfield 1987, 38 n. 2, and Wiehl 1967, n. 74 and n. 78. Many prominent commentaries-e.g., Bluck 1975, Bostock 1988, Burnyeat 1990, Chappell 2005, Cooper 1990, Duerlinger 2005, Heidegger 1997, Migliori 2007, Rosen 1983, Rijk 1986, and Seligman 1974 to in any way address these parallels. Campbell 1861 and 1867 and Gonzalez 2011 are exceptions to prove the rule both in consistently comparing the two passages and in doing so more than merely in passing. 3 Combat metaphors run throughout and frame this section of the Sophist. Notomi 1999, 217 n. 22 presents an extensive catalogue.
The Theaetetus' fluxists are similarly engaged in battle: 'There is no small fight going on about [their conception of being], anyway-and no shortage of fighting men' (179d4-5). Indeed, as a group, they form 'an army led by Homer' (153a1-2) and wage a 'most vigorous campaign' to advance their theory (179d8). For extended discussion, see Nercam 2013. 4 The giants' side of the fight grounds most of the parallels that I will draw, below, to the Theaetetus 5 On the connection between body and tangible contact, see note 11 below. 6 Note, for example, Theaetetus' emphatic responses at Soph. 246e6-247a4. 7 On the Stoics' engagement with this passage in the Sophist, see the excellent study by Brunschwig 1994. Sellars 2010, for a different assessment, is suspicious of a connection. 8 The assumption that all beings will have some one thing in common in virtue of which they are beings is accepted by all parties. It is hardly innocent, however. Aristotle's focal analysis of being is a clear, ancient alternative. Wittgensteinean family resemblance is a modern one. 9 There is a large body of literature on whether 'horos' should be translated as 'definition' or, less strongly, 'mark.' For a recent overview of and engaging contribution to the debate, see Leigh 2010. While I am inclined to think 'definition' the better option, nothing below will depend on how one decides the question. Since I am arguing for a pair of methodological claims about how one should approach interpreting the Theaetetus and the Sophist, I aim to keep substantive interpretive claims to a minimum. Beere 2009, 7. His development of the point comes in three stages. Mine, in the remainder of the paragraph, overlaps with the first of them. 11 The refined giants will later associate body with visibility as well (247b3-5). Body is similarly marked by tangibility and visibility in the Timaeus (31b4 especially). Contrast both Platonic passages with Aristotle's view, on which the primary mark of a body is instead to be extended in all three dimensions (e.g., DC I.1, 268 a 6-8). For Aristotle, tangibility is a mark of bodies not as such but only insofar as they are perceptible (GC II.2, 329 b 6-7). 12 How, precisely, the refined giants' position accommodates the earlier problem cases is not specified in the text. Crivelli suggests, plausibly to my mind, that a soul or a virtue might count as a being for the refined giants since each 'causes people to act in ways in which they would not in its absence' and thus 'may be described as having the power of affecting things in [… having] the quasi-causal power of making them be in certain ways ' (2012, 87). But what matters is simply that the refined giants' position does, somehow or other, allow them to admit souls and the virtues as beings. 13 While my argument will not depend upon the point, I agree with Burnyeat 1982, esp. pp. 5-6, with n. 2 that the basic argumentative structure of this section of the Theaetetus is a reductio: knowledge is not perception since various implications of that view are absurd. Chappell 2005, 51 shows that this conception of the argument's structure is compatible with both unitarian and revisionist readings of the text (i.e., with both the A reading and the B reading [on which, see Burnyeat 1990, 7-10]), and I intend to remain neutral with respect to those options here. 14 Socrates attributes the 'secret doctrine' to Protagoras, but the very fact that it is presented as a 'secret' raises a question about the grounds for pinning it to his historical namesake (on which, see Brancacci 2011). And indeed, as soon as Socrates raises the doctrine, he rebrands it as a kind of ancient wisdom, something with respect to which 'all the wise men of the past […] stand together' (152e2-3). In the lines that follow, Heraclitus, Empedocles, Epicharmus, and Homer are all placed in Protagoras' company. Parmenides is notable for being explicitly excepted. Melissus is later said to be in league with him (180e2 and 183e3). 15 Nor, conversely, does someone count among the initiates simply for being familiar with the theory. Socrates presents neither himself nor the fluxists' primary opponents as having been initiated. 16 I have substituted Levett and Burnyeat's translation (in Cooper 1997) of 'kompsoteroi' with an alternative from LSJ. 17 There are at least two senses of 'refined' operative in each passage. First, the refined fluxists and the refined giants are both comparatively 'gentle' in character. This sense of 'refinement' is particularly evident, I submit, in their relative willingness to engage in discussion (I comment further on this feature of Plato's presentation below). Second, the refined fluxists and the refined giants are both comparatively 'clever.' The crude fluxists are uneducated, as 'amousos' implies, as are, by their own admission, the crude giants since education, culture, intelligence, and the like are neither tangible nor visible.
In both passages, assessments of comparative refinement can be made not only synchronically (e.g., Theait. 156a2 and Soph. 246d7-8) but also diachronically. This is because the interlocutors recognize a process of refinement in each passage-namely, initiation in the Theaetetus and betterment in the Sophist (246d4-5).
The treatment of that process is perhaps significant. In the Theaetetus, nothing explicit is said about the way in which the crude and refined fluxists' respective positions are related. Yet, the initiation metaphor is suggestive. As Plato presents it elsewhere, an initiation culminates in the initiate changing her mind (Meno 76e6-9), in the face of dialectical puzzles (Euthydemus 277d-e), but by refining her positions rather than simply jettisoning them (Phaedo 69b-c). Notably, in Socrates' own initiation, that movement leads away from the particular bodies, and even body generally, that the uninitiated are presented as focusing upon (Symposium 210a-b). Admittedly, though, this reconstruction is too speculative to count as compelling, let alone decisive, evidence of a parallel.  taton].' On the other hand, he denies that the difficulty in talking with the crude fluxists is the same as that in talking with the crude giants (1867, 120); I take Soph. 246d6, quoted above, to meet the worry he raises. 22 An anonymous referee rightly notes that Theaetetus 179e-180c, on which I have drawn both in this paragraph and the one prior, does not unambiguously refer to the crude fluxists. An important indicator that this is, indeed, the way to take the reference comes in Theodorus' description of those in question as those 'who profess to be adepts [prospoiountai empeiroi]' (179e4-5). Since 'prospoieô' connotes pretending (LSJ points to Gorgias 519c3 for this coloring of the verb), the description can be paraphrased as 'those who profess to be but are not in fact initiates.' 23 The crude fluxists go on to deny 'that actions and processes and the invisible world in general have any place in reality' (155e5-6). The last component of that de-nial reveals a conception of body as tangible and visible, in that order. See note 11, above. The first two components further liken them to the crude giants, who also do not admit capacities, unlike their refined compatriots. On this point, I disagree with Benardete, who takes the crude giants to 'deny […] the changeable' (1984, I.108). They deny changes (or, at least, deny that changes are fundamental), not the bodies capable of change. 24 Campbell 1861, 50 n. 6; 1867, 123 n. 1 is particularly sensitive to resemblances among Plato's formulations of the crude fluxists' and giant's positions. 25 Sedley 2004, 46 n. 9 notes the parallel; Diès 1992, 109 n. 3 links the passages I use to support it. Whether this is merely a matter of presentation is a separate question that I will not here address.
It is notable for Plato to develop a position on behalf of no one in particular. Indeed, Brown 1998, 182 observes that, in the early and middle dialogues, Plato is unlikely to develop a position even on behalf of a determinate proponent who is neither participating in the conversation nor present for it. 26 Protagoras and others are no doubt regularly associated with the doctrine, but at critical junctures it is explicitly wrested from them and developed independently. Presumably in relation, the refined fluxists' central tenet is called a 'veiled truth' (155d10) hidden within what was already said to be a 'secret doctrine' (152c10). 27 Ross 1953, 102-103, Benardete 1984, II.41 n. 65, Sedley 2004, 46 n. 9, Centrone 2008, n. 107, and Karfík 2011 are among those who liken the refined fluxists' and refined giants' respective doctrines. While the parallels that I will present are perhaps insufficient to completely bridge the gap between capacity and motion, and so to simply identify the two doctrines (on this point, see Gonzalez 2011, 69-70), they reveal deep and pervasive agreements between those doctrines that are, I submit, sufficient to motivate the pair of methodological theses that I ultimately have in view. 28 On the significance of a commitment to a single criterion, see note 8, above. 29 Gonzalez notes the parallel, observing that, in both passages, 'all things are identified with a dunamis of either ποιεῖν or παθεῖν ' (2011, 70). 30 While, so far as I can see, there is no cause to doubt that, for the refined fluxists, all actions and passions are motions, the status of the converse claimthat all motions are actions and passions-is less certain. Though I suspect the refined fluxists would accept it as well, I am not relying on the latter claim for the parallel in the body of the paper. 31 Similarly, in a related context, the Visitor glosses 'action and passion' as 'motion' and 'that which acts or is acted upon' as 'that which moves' (Soph. 249b2). The inference in the body of the paper, it bears noting, is not presented directly on behalf of the refined giants. Rather, Theaetetus and the Visitor treat it as an implication of their doctrine when demarcating them from the friends of forms, who accept a qualified form of the doc-trine. I discuss the evidential import of the passage below. 32 Leigh 2010, 76 emphasizes this point in her discussion of the Sophist. It is not trivial that capacities should be conceived of exclusively as capacities for motion. Focusing on the Sophist as well, Beere 2009, 12-13 proposes that the difficulties arising in relation to this position prompt Aristotle to introduce both activities that are not also motions and, with them, capacities that are not also capacities for motion.
This link between capacity and motion may also help to explain why, in the Sophist, the giants' opponents, the friends of forms, might present their own position as denying that being has any share of motion, rather than as denying a claim about capacities directly. Just as the fluxists' opponents proclaim that being is 'unmoving' and 'stands still' (Theait. 180b2, 180e1-3, and 183d1), the friends of forms maintain that 'being always stays the same and in the same state' (Soph. 248a12). 33 The systematic coupling of capacities for action and passion, though not uncommon in the corpus (see, e.g., Rep. VI, 507e6 ff. and Leg. X, 903b4-9), is similarly nontrivial. To draw a comparison with the Charmides, it would preclude a capacity, like knowledge, from acting upon itself (cf. Barnes 2001, 79). 34 Seeck 2011, 78 n. 70 draws a related parallel to Theait. 184b7-185a7. 35 I owe the impetus for this paper to Charles Kahn and Susan Meyer, who encouraged me to develop and support its central thesis, a version of which I had rather flatly asserted in a footnote to my doctoral dissertation. I am also grateful to Francisco Gonzalez, two anonymous referees, and audiences at Portland State University and an SAGP meeting at Fordham University for comments on drafts.