Chapter 15 - Contested Concepts

Summary

‘Contested Concepts: Plutarch’s On Common Conceptions’ by Thomas Bénatouïl addresses the question of how ordinary concepts, for instance a layman’s concept of a spider, intersect with a zoologist’s concept of that insect. While from the epistemological point of view the latter’s concept should be allowed to prevail, from the point of view of semantics and the philosophy of mind it is not at all obvious that the scientific concept of spider should be allowed to rule over the corresponding lay concept, nor is it obvious that there is only one concept of spider whose content can be fixed for every context. Clearly, the Academics and the Stoics were aware of the importance of this and related problems. Plutarch’s dialogue On Common Conceptions, subtitled Against the Stoics, is a representative text of these schools’ respective stances, and its study by Thomas Bénatouïl aims to bring out both its historical significance and systematic interest.

1 Introduction

What is the content of a concept? While it might not always be easy to get hold of the content of a suitcase or of a book, we have ways to make sure something is or is not ‘in’ these ‘containers’. But the content of a concept is much more elusive and this very notion might turn out to be a metaphor, and a misleading one at that. When two persons do not put the same items ‘in’ or ‘under’ a concept, for example if one considers spiders as insects and the other does not, or one requires insects to ‘have six legs’ while the other just holds them to be little creepy animals, who is right about the content of the concept of insect? If this question merely asked who should be allowed to settle this matter, it would be easy to answer: the person who learnt zoology should prevail because she knows more and better as far as very little animals are concerned. But the other person has a concept of insect as well, as witnessed by the fact that it intersects with the scientific concept of insect (i.e., that their references largely and not accidentally overlap). While entomology can legitimately claim to offer a more accurate concept of insect, should it be allowed to rule over the actual content of the common concept of insect, which people have sometimes called the conception(s) of insect? Is there even one and only one concept of insect, the content of which can be fixed once and for all? Such claims are reasonable, but they can be disputed. If this assessment seems tantamount to relativism, switching to another example such as justice, the concept of which is just as common but more abstract, more disputed and not obviously defined by any science will, I hope, make a prima facie case for the relevance of these problems. Some philosophers have indeed claimed that ‘there are concepts which are essentially contested, concepts the proper use of which inevitably involves endless disputes’.¹

Many Hellenistic and Imperial philosophical debates might be taken as instances of such disputes over abstract and appraisive concepts such as the good, god, the world, happiness or virtue. Each of the main philosophical schools assessed the content of these concepts in its own way and claimed to be its only correct user. Our best source about this issue taken in itself or as a whole, rather than through an application to a specific concept or fields of inquiry, is Plutarch’s dialogue On common conceptions (Peri koinon ennoiōn), subtitled Against the Stoics, which is part of a group of three antistoic works probably written by Plutarch early in his philosophical career.

The dialogue starts with a complaint, by one anonymous interlocutor to his companion Diadumenos, about the very harsh criticism made by some of his Stoics acquaintance against the Hellenistic Academics: they were ‘sophists’ or ‘corrupters of philosophers’ bent on conflating and overturning common conceptions (1058A), which the Stoic Chrysippus successfully defended. Diadumenos answers by blaming the Stoics for contradicting and distorting common conceptions, and then asks his companion whether he prefers to engage in a refutation of the Stoics on this score or to defend the Academics from the same charge. Keen on taking revenge, the companion chooses the former (1059A), and Diadumenos launches a long attack on various Stoic doctrines. On common conceptions (Comm. not.) has generally been thought to be of interest only insofar as it testifies about these doctrines and echoes Academic (probably Carneades’) objections to them.² This chapter will entirely leave these matters aside and focus on the method and underlying epistemology of Diadumenos’ argument in Comm. not., which have attracted little philosophical attention and, when they did, were often criticised as flawed. However, read on its own terms, the dialogue can be shown to rely on relevant features of common conceptions, Stoic or otherwise, in order to raise genuine second-order problems about concepts. I will first outline the structure and the types of concepts targeted by Plutarch, then show his focus is indeed common concepts (rather than common sense) and analyse the motivations, standards and strategies of Diadumenos’ attacks. This will lead me to inquire whether his approach to common concepts can be traced back to the New Academy or includes elements of Platonism, and to emphasise Plutarch’s articulation against Stoicism of the need for an actual theory of concepts.

2 Plutarch’s Elusive Common Conceptions

The dialogue deals first with Stoic ethical doctrines, which are attacked from 1059B to 1073D (chapters 4–29). Diadumenos then explicitly switches to physical questions (chapters 30–50) until the end of the treatise, which is quite abrupt. The first part also includes discussions concerning providence (1065A–1066C), since they are related to the nature of good and evil, and the second part starts with a debate about the god(s) (1074E–1076F), then addresses ‘more physical’ matters (1077A4) and deals also with the soul (1083A–1085B), even veering on epistemology (1084F–1085B), as we shall see (pp. 363–365).

On these topics, Diadumenos blames various Stoic doctrines for going against common conceptions. It might be useful to scrutinise his expressions. He opens several chapters by asserting that Stoic positions are para tas koinas ennoias, ‘at odds with common conceptions’³ (chapters 4, 8, 10 at 1063A, 20 at 1068C, 21, 25 at 1070E, 28, 30 at 1074B1, 39 at 1080D, 43, 45, 46, 47). The plural suggests that the Stoic tenets under review are incompatible with various unspecified ideas or concepts. More frequently, Plutarch opens his chapters by introducing a Stoic position as para tēn koinēn ennoian in the singular (chapter 5–8 at 1061E, 9 at 1062D, 11, 26, 27, 30, 35, 37, 38, 40, 41, 44)⁴. While we would expect to be told which concept is concerned, we are not. Therefore, in nearly all chapters of Comm. not., Plutarch does not specify explicitly which concept(s) he uses as standard(s) to assess Stoic doctrines.

A natural interpretation is that Plutarch leaves these concepts implicit because they are easy to spell out from the context. For example, in chapter 38, Diadumenos says that it is para tēn ennoian that there should be no extremity nor a first or ultimate part ‘in the nature of bodies’ (1078E8: en tēi phusei tōn sōmatōn), so he must be dealing with the concept of a body. In the previous and next chapters, the case is less clear-cut. For example, in chapter 37, we read (1077E4): ‘let us see how the Stoics treat the subject of the elements. It is at odds with the common conception for one body to be place for another and for one to pass throught another if void is contained in neither…’. We might at first glance infer here that the standard is the concept of element, but it is in fact probably again the concept of a body, as confirmed by this chapter taken as a whole. Chapter 40 about contact and indivisibles must deal as well with the concept of a body, which would be the common topic of chapters 37–40. We can also easily guess that chapters 41–43 are concerned with the concept of time, and that chapter 35 is about the concept of a seed (sperma). As for the previous group of chapters (31–34), they deal explicitly with the concept of the gods⁵.

In other instances, it is much more difficult to understand which concept is targeted. In chapter 30, for example, Diadumenos starts by stating that ‘in general, it is absurd and contrary to the conception’ that something is but is not a being (1073D11), but he then focuses on the case of the Stoic ‘all’ (to pan), to which the former paradox applies but which has also several other absurd features. Is the concept of being or the concept of the ‘all’ concerned here? The concepts of a body and of movement seem also to be at stake in the ensuing arguments. This is perhaps picked up when Diadumenos remarks, using this time the plural, that ‘one could not even dream of [ideas] more contrary to common conceptions’ (1074B1). He then goes on to argue about other features of the ‘all’, and suggests asking all men ‘how they conceive of nothing (ti noousi to mēden)’ (1074C6–7), thus introducing another concept in the discussion. At the very least, Plutarch is here gesturing at several different concepts in the same chapter.

When one considers ethical chapters (4–29), the identification of the concept(s) presupposed by Plutarch becomes often more difficult. The concept(s) of good and/or evil seem to be relied upon in most, if not all chapters, and this is sometimes clear enough (chapters 6–8) and once made very explicit, when Plutarch opens chapter 24 by explaining how ‘in general, all men conceive of the good’ (1070B2: καθόλου τἀγαθὸν ἅπαντες ἄνθρωποι νοοῦσιν) and by confronting the content of this shared conception with ‘the good laid out by these people’ (1070B3–5). But other arguments do not refer only to the good. Chapter 26 deals chiefly with the goal of life (telos) and chapter 28 is clearly concerned with the concept of love, but chapters 5 and 11 refer to tenets going ‘against the conception’ in their first sentence, but hardly make clear whether this concept is only the concept of the good or (in the case of 5) the concept of nature or (in the case of 11) the concept of happiness⁶.

What can we conclude from this survey? First, from a linguistic point of view, the phrase παρὰ τὴν κοινὴν ἔννοιάν in the plural or in the singular is formulaic and stands by itself not in need of any precision as to its reference.⁷ It refers to a typical intellectual failure or weakness. When we claim that a position is counterintuitive or goes against common sense, we do not need to explain which intuition or which aspect of common sense is incompatible with it. But would we be able to specify this? We rather refer to common sense as a general standard, akin to a background which does not lend itself to analysis. When Plutarch claims that various Stoic tenets ‘are at odds with common concept(s)’ without specifying which one(s), could he be doing the same thing and look over the specific concept(s) at stake in his arguments? This would raise the suspicion that concepts might not be really involved in his use of the procedure in Comm. not. and that Plutarch might be merely accusing the Stoics of not following an elusive and vague common sense.

Such a suspicion has been harboured by Daniel Babut (1969: 36–45) chiefly about the physical section of Comm. not. Babut sharply distinguished the accusation of contradicting common conceptions leveled in Comm. not. from the accusation of contradicting ordinary experience (sunētheia), which is referred to in the introduction of the dialogue and which was probably developed in Plutarch’s lost treatise Peri sunētheias pros tous Stōikous.⁸ In the first ethical section of Comm. not., according to Babut, Plutarch takes issue with the Stoics for relying upon various common conceptions and then defending tenets incompatible with them. Plutarch would therefore focus on contradictions, within the Stoic doctrine, between their starting-points and their conclusions. In the second section about physics, Babut is surprised to find many charges of defending absurdities (atopia) and being at variance with ordinary experience, and he claims that Plutarch must have drawn those materials from a different source and anticipated his attack on Stoicism from the point of view of ordinary experience.⁹ We must investigate these charges.

One of Babut’s main argument (1969: 40, 2002: 24) is that Diadumenos and his interlocutor forego arguing against Stoic extravagance (atopia) in 1060A13–B9 and would thus change their plans when they denounce Stoic atopia later (for example in 1074D10, 1075C1 or 1078E). But 1060B does not eschew all objections against atopia, but only the well-known criticism of these positions that the Stoics themselves call ‘paradoxes’ and acknowledge to be extravagant (1060B1). Diadumenos commits only to a focus on central and serious Stoic doctrines (1060B5). Similarly, in 1083A7, Diadumenos does not say that he overlooks all absurdities in favor of disagreements with common conceptions (Babut 2002: n. 677), but that he will neglect many absurdities which are not at odds with common conceptions and focus on those which are (for example 1072F9–10 about love). Let us try to understand how these extravagances and absurdities happen according to Diadumenos.

3 Challenging the Commonality of Concepts

Common conceptions are basic notions which the Stoics claim to use as points of departure for philosophical teaching and arguments¹⁰. One could never prove that virtue is the only good or that there is ultimately only one perfectly rational god by appealing to common sense, but the Stoics claim this is possible by relying on a basic and widespread conception of the good as what is beneficial, or of god as an immortal, blessed and providential being. Plutarch does not use the Stoic distinction between a conception and a concept and defines a ‘conception’ as ‘a type of representation’ (1084F); ‘common conceptions’ are therefore representations shared by most, if not all, adult human beings. This commonness is however taken as strong evidence that they are objective concepts.¹¹ This is why I proposed (in Section 1) to understand Diadumenos’ claims that the Stoics are ‘at odds with common conception’ X as charging them not only with disagreeing with widespread judgements or opinions about X, but also with contradicting the natural concept of X. While the customary English translation of ennoia by ‘conception’ will be used in this chapter for koinē ennoia, a more ambivalent translation such as ‘common notion’ would better fit Diadumenos’ uses of this idea, and I will often paraphrase them by referring to ‘concepts’, that is, the objects or intentional contents of conceptions.

Common conceptions consist therefore neither in common sense nor just in any concept defined by the Stoics,¹² but are concepts grasped in principle by all human adults. It does not mean that anyone would understand immediately a common conception were they asked about it. Nevertheless, the prima facie content of such a concept must be accessible to all of us, philosophers and non-philosophers alike. It would be foolish to claim that all human beings have a conception of virtue as a coherent disposition of the governing part of the soul or of god as universal reason shaping matter,¹³ but they all grasp the meaning of the words ‘virtue’ and ‘god’ and are acquainted with the main features of virtue and god. Common conceptions are therefore basic notions, the primary or core content of which can and should be assumed in philosophical arguments, because it is putatively shared by all human beings and provides a neutral ground or natural standard that all philosophical doctrines should take into account.

Still, one can dispute that a conception is indeed a common conception if one judges that the content a philosopher attributes to this notion does not capture any feature of its natural use(s) or falls short of these uses. This is what happened, according to Diadumenos, in the debate between the Stoics and the Epicureans about gods:

Moreover, the Stoics themselves make no end of fuss crying woe and shame upon Epicurus for violating the preconception of the gods (sunkeonta tēn tōn theōn prolēpsin) because he does away with providence, for they say that god is preconceived and conceived (prolambanesthai kai noeisthai) to be not only immortal and blessed but also humane and protective and beneficent. This is true.¹⁴

The Stoics challenged the commonality of the Epicurean conception of god or rather of the Epicurean spelling out of the content of the concept of god,¹⁵ arguing that the Epicureans ignored a crucial part of this content. I shall come back shortly to the criterion which can be used in such a debate over the very content of a shared concept. But I must first emphasise that De Comm. not. testifies clearly to the fact that the Stoics already accused rival schools of being at odds with common conceptions (and were surely charged with the same failure in return).

Besides the example of the preconception of god, Diadumenos mentions similar accusations of ‘violating conceptions’ or ‘destroying preconceptions’ and ‘being at odds with common conceptions’, made by Stoics against the Epicurean claim that all atoms move at the same speed (1082E) and against the Academics (1083A9–B2). And a similar more general charge was brought against the ‘older Academics’, namely Arcesilaus and Carneades in this context,¹⁶ by Stoic acquaintances of Diadumenos’ companion (1059B1–2).

In these attacks, the Stoics are supposed to have appealed to various standards on which common conceptions were thought to be grounded. In the chapter just mentioned about the Academic analysis of growth, Diadumenos refers to the Stoics as ‘these advocates of evidence and standards of [common] conceptions’ (1083C4: οἱ πρόδικοι τῆς ἐναργείας οὗτοι καὶ κανόνες τῶν ἐννοιῶν). This is an ironical description in the context of his attack on their outlandish doctrine about growth, but it probably captures the criterion they used in their own polemics against rival schools. In another chapter, Diadumenos complains that ‘they belittle and disparage [the rest of us] as if they alone uphold nature and ordinary experience as it must be done and alone put reason in a position to avert all else and to bring each man by his desires and pursuits and impulses to that which is appropriate’.¹⁷

This is not the place to investigate whether these testimonies on the Stoics are corroborated by other sources, but I do not see reasons to doubt their overall reliability. While some Stoics might not have been keen on appealing to ordinary experience (sunētheia) or to what all human beings think or do¹⁸, how could they not fall back on these or similar standards when confronted with other schools appealing to, as it were, their own common concepts, that is to say (a) claiming like the Stoics to rely on natural concepts but (b) attributing to some of them a different content, from which (c) they could defend views opposed to the Stoic ones. What remains uncertain is when such a Stoic counterattack happened. It is possible that Plutarch refers in the texts just quoted not to Chrysippus but to Stoics posterior to Carneades or even only to first century ce Stoics, such as the friends who upset Diadumenos’ interlocutor, as he reports in the first page of the dialogue.¹⁹

4 Is Diadoumenos’ Attack ‘dialectical’?

Whatever the past history of the debate over common conceptions may have actually been, Diadumenos describes it as emerging both from the very nature of common conceptions and from their Stoic (and Epicurean) uses. Moreover, he states that he is firing back at the Stoics with their own weapons (1059E–F). Does this mean that Diadumenos’ whole attack is only dialectical, that is, based on premises or assumptions borrowed from his Stoic targets but not endorsed by himself? This is indeed often what happens in the dialogue, and Babut goes so far as considering the charge of being at odds with common conceptions and the charge of contradicting oneself as de facto identical in De Comm. not., because Diadumenos often notes that the Stoics are at odds not only with the common conceptions but also ‘with their own’ conceptions (1062a, 1068c–d, 1070e). But this very remark implies that these are two different charges, and they both apply only when it can be shown that²⁰:

1. (a) a Stoic doctrine is incompatible with the content of one common concept

2. (b) The Stoics agree explicitly or implicitly with the content of this concept

   Therefore

3. (c) Stoicism is both at odds with this common concept and with itself

Such a pattern underpins explicitly many ethical and physical chapters of Comm. not. (for instance chapters 6, 8, 9, 25, 27, 32 and 35). In many chapters however, Diadumenos skips step (c), perhaps because Plutarch could not find any Stoic doctrine acknowledging the common concept(s) he wants to blame the Stoics for ignoring. Examples include chapters 5, 7, 11, 13, 24, 26, 30, 31 and 33. In these cases, Diadumenos’ argument is not dialectical but blames the Stoics for disregarding or ruining conceptions that he himself holds to be common and worthy of philosophical respect. He indeed often emphasises their widespread use and the ensuing peculiarity of Stoic doctrines that ignore them. If we read Comm. not. with a view to the criteria Diadumenos appeals to in order to establish this discrepancy, we can find the following:

Empirical experience. In chapter 35, Diadumenos argues that ‘it is at odds with the common conception to say that a seed is ampler and bigger than what is produced from it’,²¹ by noting that ‘we see nature’ using tiny seeds ‘in all cases, whether plants or animals’ (1077A6–7), and by giving specific examples of this.²² This is a good but rare example of a common notion straightforwardly obtained from sensations. When the content of an empirical common conception is ignored by the Stoics, we can thus turn back to the phenomena from which it originates.

Diadumenos also appeals to enargeia²³ to refer to something manifest to reason, akin to a logical truth (1074B2, 1079A4, 1079F7, 1084B). He sometimes claims that no human being can ‘think’ or conceive various Stoic ideas (1081A, 1083C) or appeals to what ‘all human beings know and think, provided they have not become Stoics’ (1079A)!²⁴ This is probably what Diadumenos jokingly refers to, after dealing with Stoic theology, when he says he now leaves the gods ‘with a prayer for the gift of common sense and common intelligence’.²⁵ As already suggested, we should not take Plutarch’s reference to all human beings in the strict sense, not only because he had no means to poll his contemporaries about their opinions, but also because he is ready to refer to ‘the common conception of principle and element bred in practically all human beings’ (1085B: πᾶσιν ὡς ἔπος εἰπεῖν ἀνθρώποις ἐμπέφυκεν)’. Even taking into account the qualification adduced by Plutarch, one can doubt that the conception of a principle or element as something ‘simple and unmixed and incomposite’ was widespread. The reference might be here rather to all learned adults, which would be anyway in line with what common conceptions are supposed to be²⁶.

Sunētheia is another similar criterion to assess common conceptions (1063D9, 1070C1, 1084B). Diadumenos even uses it to caracterise common conceptions ignored by the Stoics²⁷. Its scope is fairly wide and its meaning often not easy to ascertain, since it refers to an habitual experience or practice, from ordinary perception²⁸ to linguistic usage²⁹ and customs.³⁰

Diadumenos also sometimes blames the Stoics for disregarding ‘nature’ in their discourses or doctrines (1064A, 1070A, 1071D), a criterion which, in this context, seems to refer mainly to natural, that is, spontaneous and universal, human behaviour, such as pursuing goods and avoiding evils. He also once refers to ‘the utter overthrow and ruin of the facts’ by what the Stoics say about the aims of our actions.³¹ These facts seem to be then subsumed under the criterion of ‘nature’, which is referred to a few lines below.

Disputes about common conceptions can therefore be conducted and, if possible, settled only on the basis of other prior standards. Our conceptions are derived from sources³² which we need to fall back on in case of disagreements about their content or commonality. What are we to make of these standards assumed by Diadumenos in his attacks? While many of them, were probably already used by the Stoics, as noted above (p. 353), Diadumenos seems hardly content with borrowing them, that is to say turning them against the Stoics without assenting to any of them. On the contrary, he appears to agree with the Stoics, throughout the dialogue, that common conceptions should be preserved by philosophers and therefore to defend them on the basis of these various standards.

5 Diadumenos and the New Academy on Relying upon Common Conceptions

This might however be thought to be very unlikely in the context of Diadumenos’ Academic affiliation. Not only are strictly dialectical arguments often supposed to be the standard practice of the New Academy,³³ but the very first sentence of the dialogue seems to exclude the reading just offered of Diadumenos’ position:

You are in all likelihood quite unconcerned, Diadumenos, if anyone thinks that your philosophy is at odds with common conceptions. After all, you admit that you disdain the senses themselves; and from them have come just about most of our conceptions, the secure foundation of which is, of course, confidence in phenomena.³⁴

This is not confirmed, to say the least, by the ensuing dialogue in which Diadumenos challenges the Stoics in the old but still ongoing competition for the title of ‘advocate of evidence and standard of [common] conceptions’ (1083C4). How can we account for this discrepancy? Either we must suppose that Diadumenos concedes the value of common conceptions to Stoicism and that, despite using Carneadean objections to various Stoic doctrines, his approach is not Academic, or we could consider the possibility that challenging the reliability of common conceptions as such is not crucial to the New Academy and that Plutarch might still be following in its footsteps when championing common conceptions against the Stoics.

This second option becomes more plausible if we notice that the claim made by Diadumenos’ companion is cast in hypothetical terms. He only makes a guess as to Diadumenos’ lack of reaction to the accusation he himself suffered, based on Diadumenos’ Academic mistrust of the senses and on the dependency of conceptions on them. I suggest this guess reflects (in Plutarch’s mind) a simplistic view of the New Academy as a radical scepticism indifferent to common conceptions, put forward at the outset of the dialogue by an obviously younger or, at least, philosophically less advanced interlocutor to his mentor,³⁵ who then corrects it. Diadumenos’ ensuing suggestion that he could defend the Academics (and therefore himself) from the Stoic charge of being at odds with common conceptions (1060A1–2) is in fact serious³⁶ and implicitly carried out in the dialogue.³⁷

Can we support Diadumenos’ claim about the Academy by independent evidence?³⁸ Our best source about the epistemological debate between Stoicism and the New Academy is Cicero’s Lucullus. In this dialogue, Lucullus first presents Antiochus’ epistemological doctrine, which is generally thought to be quite similar to Stoic epistemology. Lucullus lists conceptions just after sensory perception (19–20) and before arts, virtues, wisdom, reason and logic (22–27) in his thorough survey of our sources of knowledge, aimed at showing that the Academic denial of ‘apprehension’ (katalēpsis) is utterly untenable.³⁹ In his rebuttal on behalf of the New Academy, Cicero answers Lucullus’ claims about the senses and about reason and logic, but does not offer any objection against conceptions as such.⁴⁰ This silence can be understood either as an oversight, or as a sign that Cicero judges that the attack on sensation is sufficient to undermine natural notitiae (which originate in sensations), or as a hint that they should be spared. The first option is implausible, given that Cicero disputes most of Lucullus’ arguments, including the one about memory offered in the very paragraph about conceptions (Luc. 22 refuted in 106).⁴¹ The second option would confirm part of Diadumenos’ interlocutor’s hypothesis: the Academics would challenge common conceptions only insofar as they derive from sensations but not in themselves.⁴² The third option would go further and imply that, despite their unreliable empirical origin, common conceptions can be maintained as standards, which would not amount to conceding to Lucullus that they are true, but only that philosophers should not feel entitled to contradict them.

While this third option is only a possible inference from Cicero’s silence about conceptions in his defence of the New Academy in the Lucullus, it fits Diadumenos’ position perfectly:

Why then, my dear sir, are we now trying to do anything else but convict their school of doing violence to our common conceptions and turning them inside out with considerations which are not plausible and words which are unfamiliar?⁴³

This is Diadumenos’ answer to his companion’s charitable remark that the Stoics have a definition of love as ‘a kind of chase after a stripling who is undeveloped but naturally apt for virtue’. This explains why they disregard physical beauty and ugliness when dealing with love. Diadumenos does not think this mitigates their failure, since ‘one ought to call “love” what all men and women understand and call by the name’ (1073C5–6). This is a defence not only of ordinary linguistic usage against a Stoic paradox, as claimed by Babut (2002: 26), but of ‘our common conceptions’ (my italics), namely the notion of love shared by all men and women, including Diadumenos and his fellow Academics, to which the Stoics should stick. This defence surely does not require Diadumenos to trust these conceptions as much as the Stoics or ordinary people do, but he clearly endorses them as worthy of being preserved and in some way reliable. The fact that he blames the Stoics for adducing ‘implausible considerations’ (οὔτε πιθανοῖς) is perhaps a reminder of his non-dogmatic epistemological standards: following Carneades, Diadumenos would want to preserve the common conceptions only because they are persuasive and seem to be true.⁴⁴

Diadumenos’ complex position is also revealed in his description of the Stoic dismantling of religion (1074E, trans. Cherniss):

They ought above all to have straightened out and set to rights the conceptions about the gods by repairing [anything] in them that may have become confused or have gone astray but otherwise ought to have let people persuaded by the law and ordinary experience be each as he is in his relation to the divinity (…). But instead, they began to upset from the very hearth and foundation, as it were, the established traditions in the belief about the gods and, generally speaking, they have left no conception intact and unscathed

(οὐδεμίαν, ὡς ἁπλῶς εἰπεῖν, ἔννοιαν ὑγιῆ καὶ ἀκέραιον ἀπολελοίπασι)

Babut (2002: 265, n. 452) thinks Plutarch here acknowledges (against the Stoics) that common conceptions can be wrong, because they depend on ordinary experience. But τὰς περὶ θεῶν ἐννοίας in the plural probably refers not to the preconception(s) of god,⁴⁵ but to the various conceptions of divinities coming from different cultures, which philosophers can legitimately set straight. However, traditions and laws are better left intact than criticised in favor of paradoxical philosophical doctrines, which turn the gods into mortal beings. While this argument might be traced back to the New Academy, at least as far the handling of ordinary and philosophical opinions about the gods is concerned,⁴⁶ it also probably goes beyond any Academic argument when it suggests that there is indeed a naturally sound conception of god,⁴⁷ and this probably stems from Plutarch’s conception of Platonism as being on the side of common sense against the Stoics and the Epicureans.⁴⁸

6 Articulating Concepts? Meno’s Paradox and Stoicism

To take stock of this Platonist strand in Plutarch’s criticism of Stoicism and to inquire whether it plays a role in Comm. not, we must broach fragment 215, attributed by Damascius to Plutarch:

(e) that both seeking and finding illustrate recollection for one cannot search for something of which one has no notion (an tis hou estin anennoētos) or find it (…). (f) that the question raised in the Meno whether it is possible to seek and to find is a real problem (…). The Peripatetics came up with the idea of potential intellect: but we were worried about actually knowing and not knowing. Let there be ‘potential intellect’: still the same problem persists. How does this intellect think. Either it thinks things it knows or things it does not know. The Stoics explain it by natural conceptions (tas phusikas ennoias). If they are potential, we shall say the same thing; if they are actual, why are we seeking what we know? If we start off from these for other things we do not know – well, how, since we do not know them? The Epicureans appeal to preconceptions: but if they say that these are articulated (diērthrōmenas), searching is unnecessary: if they are not articulated (adiarthrōtous), how can we seek for something beside the preconceptions which we have not previously conceived?⁴⁹

The text seems to turn each post-Platonic school against the other so as to eliminate all available rivals to Plato’s doctrine of recollection as a solution to Meno’s paradox (Meno 80d). First, the Peripatetics posit only a potential intellect and do not account for the achievement of actual knowledge. The Stoic natural conceptions then fall into this potential/actual dilemma. If the Stoics try to escape it by arguing that their conceptions are only starting points for securing real knowledge, then the paradox applies again to this endpoint (we do know yet what we search if conceptions are only stepping-stones). The Epicureans seem to be blamed again for the same problem but cast this time in Stoic rather than Aristotelian terms, since the idea of ‘articulation’ is Chrysippean.

This idea captures a crucial aspect of the Stoic approach to the problem of discovery and learning.⁵⁰ It accounts for the transition from natural conceptions to actual knowledge by providing a method starting from the basic content of a preconception (formed naturally through experience) of an object to the scientific grasp of the concept of the same object.⁵¹ Meno’s paradox does not apply, because we search for X on the basis of its natural conception (which allows us to identify X but not to know it) and discover what X is by digging, so to speak, into the content of this conception: we work out its logical implications, test to which particular objects they apply or do not apply and ultimately integrate this conception in a tight network of other articulate conceptions, which amount to knowledge. In terms of the debate set out by Robert Brandom about how to account for the content of concepts, the Stoics try to combine representationalism (natural preconceptions) and inferentialism (dialectical articulation).⁵²

While Diadumenos’ interlocutor mentions Chrysippus’ articulation of conceptions when he recalls his Stoic friends’ abuse,⁵³ Diadumenos himself ignores this dialectical process, just as the objections in the fragment quoted. As we have seen, he very often contrasts complex Stoic doctrines with common conceptions formed on the basis of our experience and which the Stoics acknowledge as sound. He thus overlooks their claim that one can progress from the latter to the former thanks to dialectic.⁵⁴ This is a crucial move, which is only alluded to in 1073D: Diadumenos forecasts a criticism of Stoic dialectic (see note 8 above) for using ordinary experience as a ‘filter’ (διέραμα) and ruining it like an ear made sick and deaf by ‘empty sounds’. Logical articulation cannot complete and perfect natural experience but only ruin it. This is a typically Academic, and probably Carneadean, move challenging the continuity posited by the Stoics between nature (sensations, impulses, the world around us) and reason (knowledge, virtue, divine providence)⁵⁵ and the ability of a purely formal dialectic like the Stoic one to yield any knowledge.⁵⁶ It might seem hardly compatible with Platonism, since recollection consists in a similar intellectual process, drawing us as it does from ordinary perceptions to intellectual knowledge. But the very point of recollection is that this progress is only apparent, since its real starting point is not perceptual experience or even common conceptions but a prior actual knowledge of Forms by the immortal soul, which has been forgotten and is only rekindled by perception or teaching. Stoic articulation is a form of discovery, through the logical structuring of our experience, while Platonic recollection amounts to a recovery of its own intellectual assets by the soul. But do we have direct evidence that this Platonic inspiration underlies Diadumenos’ Academic arguments against Stoic common notions? I think we do.

7 Diadumenos’ Conception of a Concept and its Platonist Background

Chapter 24 makes explicit the concept of good shared by ‘all human beings’ (1070B) and then lists actions of the Stoic sage which do not fit the accepted features of the good. Diadumenos then concludes (1070C–D, trans. Cherniss slightly modified):

Has there ever been another doctrine which did greater outrage to ordinary experience, itself snatching away and abducting the genuine conception like babes from her breast, while substituting other spurious ones, brutish and uncouth, and constraining her to nurse and to cherish these in place of those – and this too in matters concerning good things and evil and objects of choice and avoidance and things congenial and repugnant, the clarity of which ought to be more manifest (σαφεστέραν ἔχειν τὴν ἐνάργειαν) than that of things hot and cold and white and black, since the representations of these are not incidental to the sensations entering from without, whereas the former are generated intrinsically from the starting-points within us

(ἐκείνων μὲν γὰρ ἔξωθέν εἰσιν αἱ φαντασίαι ταῖς αἰσθήσεσιν ἐπεισόδιοι, ταῦτα δ’ ἐκ τῶν ἀρχῶν⁵⁷τῶν ἐν ἡμῖν σύμφυτον ἔχει τὴν γένεσιν;) ?

Diadumenos likens ‘authentic (gnēsias) conceptions’ to babies fed by sunētheia, and implicitly compares the Stoic conceptions to bastard children substituted to the legitimate ones.⁵⁸ This can be read as a reference to Socratic midwifery, which, in the Theaetetus, aims at examining newborn opinions, delivered from the soul of the interlocutor, and at getting rid of the fake or bastard ones, which cannot resist refutation.⁵⁹ The Stoics are blamed from doing just the opposite. This analogy seems at first perfectly in line with the use made by the Academics of the Socratic method of refutation vis-à-vis the Hellenistic schools and with their appeal to the Theaetetus. But Diadumenos then claims that our conceptions about good and evil should be much clearer than our sensations, because the former are generated within our soul whereas the latter come from outside. This clearly overturns the companion’s initial hypothesis that common conceptions are as unreliable as sensations according to Diadumenos. Most common conceptions discussed by Diadumenos are indeed only remotely dependent on sensations, as we have seen. Moreover, this hierarchy between contingent empirical perceptions and ideas generated within us has a Platonic flavour and confirms the hypothesis of a Platonic undercurrent in Comm. not.

Even though this has escaped the attention of commentators, in fact this undercurrent almost surfaces in chapters 27 and 47. Both happen to be located close to the end of each section of the dialogue⁶⁰ and to attack the Stoic disregard for the common conception of… a concept, as is made explicit in the opening of ch. 47 : ‘And in what they suppose to be the essence and genesis of conception itself, are they not at odds with the [common] conceptions?’⁶¹ The second-order move is less explicit in chapter 27, but is nonetheless a plausible reading of its first sentence: ‘[And since] we have come to this point in the argument, what would you say is more at odds with the [common] conception than the proposition that men, without having grasped or got a conception of good, desire the good and pursue it?’⁶² While Plutarch does not devote a section of his dialogue to Stoic logic and logical common conceptions, he nevertheless addresses the problem of the (epistemo)logical underpinning of ethics and physics. Chapters 27 and 47 argue that Stoic ethics and physics not only go against ethical and physical common conceptions, but also ignore or destroy the very conception of what a concept should be.⁶³

In chapter 27, Plutarch claims that the Stoic concept of the good is caught in a vicious circle, since prudence is defined as the science of good and evil, but the only good is virtue (in which prudence is included). The concept of prudence and the concept of the good reciprocally and completely depend on each other and are thus both empty. Plutarch can thus attribute to the Stoics ‘not only a distortion, but a dislocation of their doctrine, and a complete reduction to nullity’.⁶⁴ This fate is suffered presumably not only by the Stoic doctrine but by the common conceptions.⁶⁵ Diadumenos then makes the same point using a Stoic definition of the final end and showing that it presupposes itself and thus has no content whatsoever. The concept of the good, which should capture what motivates our conduct, is emptied of its content and thus rendered powerless in the context of Stoic ethics.

In chapter 47, the problem raised by Plutarch is the nature and development of conceptions in the soul as conceived by the Stoics. Conceptions should be recorded in the soul, first because they are representations and foremost because they are stored in the mind, like memories, and constitute the starting points of sciences, which the Stoics themselves define as ‘unalterable and steadfast’ (1085B2). But how can these intellectual fixed points be achieved in a soul which is made of air, moisture and breath? Plutarch contrasts the Stoic definitions of representations, conceptions and science on the one hand, which convey and require mental stability, and the Stoic doctrine of the soul, the stuff of which ‘is always in motion and flux’ (1085B4). Stoic physics destroys the very possibility of Stoic or any common conceptions.⁶⁶

Both chapters thus carry the charge against the Stoics one step further: not only do they distort numerous common conceptions, but their doctrines make common conceptions in themselves impossible (from a psychological and epistemological point of view) and meaningless (from a practical and ethical point of view). The implication of these charges is that a good philosophical doctrine should not only preserve and respect actual common conceptions but explain and justify their existence and value. Can we find an intimation of such a better doctrine in Plutarch’s dialogue? The end of chapter 47 unmistakably suggests that a Heraclitean conception of the soul, such as the Stoic one, is incapable of accounting for science, thus recalling the arguments of the first part of the Theaetetus and perhaps gesturing towards an alternative non-Heraclitean and non-material conception of the soul. In chapter 27, there is a similar, albeit more cryptic, allusion to Plato, when Diadumenos compares the circularity of the Stoic definitions of prudence and the good to ‘the pestle’s roundabout’ (1072B6: huperoou peritropē). This proverbial expression used to describe a ‘never-ending and ineffectual labour’ (LSJ) is used by Socrates in Theaetetus 209e to caracterise his final objection against the third definition of science, which has been shown to add to right opinion (in order to turn it into science) a logos which amounts itself to a right opinion. In chapter 27 and 47, the Stoic doctrines supposed to account for common conceptions fall prey to Platonic objections drawn from the Theaetetus.⁶⁷

Comm. not. must therefore have performed a maieutic function in Plutarch’s mind: through the refutation of Stoic views, it clears the way for a better understanding of common conceptions, both specific common conceptions in various parts of philosophy⁶⁸ and the doctrine or method of common conceptions in itself. The contrast between contingent sensations and ethical common conceptions in chapter 24 can therefore also be read as a reference to the end of the first part of the Theaetetus, where various qualities ‘common to all particulars’ (to t’epi pasi koinon), such as good and evil, are agreed to be perceived not by any bodily organ but by ‘the soul itself by itself’ (186a2–10). This suggests that Plutarch is ready to accept common conceptions as basic philosophical principles, like the Stoics, but denies their materialistic and empiricist account and their dialectical analysis are fit to explain and preserve them.⁶⁹ In Platonic Questions 1000E, Plutarch accordingly reads Socratic midwifery in the Theaetetus as aiming to deliver ‘innate intellections’ (emphutous noēseis) instead of imparting intelligence to the soul from the outside, and thus implicitly contrasts Socratic midwifery with the Stoic articulation of natural preconception and connects the former to Platonic recollection.⁷⁰