I.

Koinōnia is a multifaceted notion in Plato’s dialogues. The term covers a wide range of meanings and it is employed in very different contexts, as the list below shows.

(1) It may mean “association” (R. 333b7, 343d6; Lg. 632b4, 861e2), also in the sense of “partnership”, “friendship”, “alliance” (Lg. 695d3, 773d3; Criti. 119c5; Smp. 182c3¹, 209c5²); not by chance, the term is sometimes coupled with philia (Lg. 695d3; Smp. 182c3, 209c5; see also Grg. 507e5, ὅτῳ δὲ µὴ ἔνι κοινωνία, φιλία οὐκ ἂν εἴη, and 508a1³, where nonetheless the meaning of koinōnia is different: see (12) below). Also, the verb κοινωνέω can bear this meaning (Plt. 304a1).

(2) Broadly speaking, it may mean “community” (Lg. 921c4 (in a markedly political sense), 639c1, 639c6; Plt. 276b7; R. 466d7), also in the sense of “meeting occasion” (Lg. 639d2, 640a4, 783b6, 796a3, 834d5 and 833d3, where the term means “competition”, 881e1; R. 556c8), or even “common condition”, “common life style” (R. 466c5, see also the employment of κοινωνέω in these pages; Lg. 805d7).

(3) Generically speaking, it may refer to a form of “communication”, or “compatibility”, between abstract concepts (R. 402e3, between temperance and excessive pleasure; Plt. 283d8⁴; perhaps also Prm. 166a2⁵).

(4) It is used with regard to the “joint-ownership” of wives and children (R. 449c8, 449d4, 450c1, 461e5, 464a9, 464b6). This meaning is typical of, and limited to, the Republic.

(5) It refers to a “common perceiving” (R. 462b4, 464a6).

(6) It refers to the “communion” of soul and body (R. 462c10, 611b11; Lg. 969b7, where the “communion” at issue is the one that existing between head and intellect, 828d4; Phd. 65a2⁶). In this sense, see also the employment of κοινωνός at Phd. 65b1 and of κοινωνέω at Phd. 66a6 (and elsewhere).

(7) It is employed with reference to the participation-relationship (7a) between sensible objects and ideas (Phd. 100d6⁷; R. 476a7⁸) and (7b) between the ideas themselves, or the µέγιστα γένη themselves (Sph. 250b9, 251e8, 254c5, 256b2, 257a9⁹, 260e3, 260e5, 264e2¹⁰; see also the employment of κοινωνέω and ἐπικ0οινωνέω¹¹ in the same dialogue). As is evident, the latter meaning is absolutely preeminent in the Sophist, where it becomes nearly “technical”.

(8) It may refer to the “mutual relationship” among some specific disciplines (R. 531c10, where it is coupled with συγγένεια; Lg. 967e2¹²).

(9) It may allude to sexual relationships and marriage (Lg. 636c3¹³, 721a4, 771e1, 772d7, 773a4, 773c). As is evident, this meaning is exclusively attested in the Laws.

(10) Hardly ever does it refer to the partaking of a common “lineage” (Lg. 729c5)¹⁴.

(11) It may refer to a sort of “horizontal communication” among sensible objects, which therefore represent a “whole”, or “set” (Plt. 285b1¹⁵; see also [17] below).

(12) It can be employed with reference to the “vertical” communion between human beings and deities (Smp. 188c1¹⁶; Grg. 507e5, 508a1).

(13) It may refer to the particular kind of “dialogic communion” which is founded on logos (R. 371b6; La. 180a5¹⁷, 197e7¹⁸). In this very sense, see also the employment of κοινωνός at Ti. 20d4 and κοινωνέω at Cra. 434b9 (and elsewhere).

(14) In some specific contexts, the term refers to the “mixture” of flavours (Ti. 60d8, 61c3), or of different “species” of fire (Ti. 46a5¹⁹); see also Phlb. 25e7²⁰.

(15) It may mean “usage” (Hp. Mi. 374e3²¹; Lg. 805a2).

(16) Generically speaking, it may amount to “sharing”, or “taking part in” (Lg. 694b6 with philia, 844d4; Sph. 252b9; Prm. 152a2²²). The same meaning also arises from the verb κοινωνέω (see e.g. Sph. 248a11).

(17) Broadly speaking (once more), it can mean simply “set”, or “whole” (Ti. 87e2).

The purpose of this paper is to make the case for a theoretically strong connection between koinōnia and syngeneia/oikeiotēs²³. As the list above shows, there is only one passage where these words are coupled; but were such connection to be proved somehow relevant in one case, it would be legitimate to scrutinize if each philosophical²⁴ employment of koinōnia entails, ipso facto, some form of syngeneia or oikeiotēs. As a result, syngeneia and oikeiotēs will turn out to represent the condition of possibility for koinōnia to take place.

II.

The only text where koinōnia, syngeneia and oikeiotēs appear together comes from the Republic (531c9-d4). It deals with the disciplines in which future philosophers are expected to be trained: (T1) “And what is more,” I said, “I take it that if the investigation of all these studies goes far enough to bring out their community and kinship with one another, and to infer their affinities, then to busy ourselves with them contributes to our desired end, and the labor taken is not lost; but otherwise it is vain” (Οἶµαι δέ γε, ἦν δ’ ἐγώ, καὶ ἡ τούτων πάντων ὧν διεληλύθαµεν µέθοδος, ἐὰν µὲν ἐπὶ τὴν ἀλλήλων κοινωνίαν ἀφίκηται καὶ συγγένειαν, καὶ συλλογισθῇ ταῦτα ᾗ ἐστιν ἀλλήλοις οἰκεῖα, φέρειν τι αὐτῶν εἰς ἃ βουλόµεθα τὴν πραγµατείαν καὶ οὐκ ἀνόνητα πονεῖσθαι, εἰ δὲ µή, ἀνόνητα)²⁵.

What can be inferred from this passage, when it comes to the relationship between the three notions here at issue? On the face of it, nothing unfortunately. We are only told that there is some connection between syngeneia, koinōnia and also oikeiotēs (as the adjective oikeios suggests). Nonetheless, as for the precise nature of this relationship, Plato leaves us with no clues. But it cannot be a mere coincidence that these three words are matched in such an argumentatively crucial passage of the dialogue. As I have sketched out above (I), the hypothesis that will be substantiated hereafter is that koinōnia can take place only if there is some form of syngeneia, or oikeiotēs, among the members to be involved in the koinōnia itself. In other words, koinōnia entails syngeneia and oikeiotēs as its necessary conditions.

A reassessment of the meanings listed above is now in order. Let’s start with (1). Philia, which is a form of koinōnia, is likely to require oikeiotēs to occur. This can be inferred from the Lysis (221e), for example, where we read: τοῦ οἰκείου δή, ὡς ἔοικεν, ὅ τε ἔρως²⁶ καὶ ἡ φιλία καὶ ἡ ἐπιθυµία τυγχάνει οὖσα, ὡς φαίνεται, ὦ Μενέξενέ τε καὶ Λύσι²⁷. The same idea can be derived also from the Menexenus (243e4-244a3), where, with regard to ἡ τῷ ὄντι συγγένεια, it is said that φιλίαν βέβαιον καὶ ὁµόφυλον οὐ λόγῳ ἀλλ’ ἔργῳ παρεχοµένη. Last but not least, this very conception is clearly stated also at Grg. 507e5: ὅτῳ δὲ µὴ ἔνι κοινωνία, φιλία οὐκ ἂν εἴη.

Also, a “political community” (2) requires, broadly speaking, some form of syngeneia among its members, as the Stranger of Elea -for example - puts it in the Statesman. As a matter of fact, perceptual συγγένεια is the natural datum which brings about any immediate interhuman “association” (koinōnia); thus, moderate people only tend to gather with equally moderate people, whereas courageous people are likely to be attracted only by analogously courageous people. But this situation only paves the way to disruption -to dreadful στάσεις²⁸. Therefore, it falls upon the politician to make use of both “divine” and “human bonds” in order to artificially create “politically correct” kinship-relationships across the citizenship. In particular, the “divine bond”, which amounts to τὴν τῶν καλῶν καὶ δικαίων πέρι καὶ ἀγαθῶν καὶ τῶν τούτοις ἐναντίων ὄντως οὖσαν ἀληθῆ δόξαν µετὰ βεβαιώσεως, depends on a specific kind of “kinship” across the citizenship -namely, their sharing τὸ ἀειγενὲς ὂν τῆς ψυχῆς αὐτῶν µέρος. This is an essential and profound kind of syngeneia, unlike the perceptual one sketched out above²⁹. But also, the “human bonds” deal with syngeneia, inasmuch as they aim to harmonise different forms of virtue by means of τῶν ἐπιγαµιῶν καὶ παίδων κοινωνήσεων καὶ τῶν περὶ τὰς ἰδίας ἐκδόσεις καὶ γάµους, thereby bringing about a more heterogeneous (and artificial) net of kinship-relationships across the citizenship. As a result, the koinōnia of the polis is strong and balanced.

Moreover, the necessity to share wives and children (4) is likely to depend on syngeneia. The city must be united, since stasis is lethal to its life. In the Republic, the privileged means to reach such a purpose seems to be provided by some “unifying” myths, like that of the “Noble Lie”³⁰. This kind of tale told by the philosopher-politicians aims to persuade people of their original “kinship” (ἅτε οὖν συγγενεῖς ὄντες πάντες), which lies behind their social and intellectual differences. This fundamental fact urges them to safeguard their unity as a πόλις at any cost. Therefore, their being all “akin” to one another cannot but result into the “communion” of wives and children, thereby neutralizing the risk of egoism and corruption.

(6) is a revealing case study. Actually, soul and body are anything but “akin”, or “cognate”; nevertheless, they are often said to hold a koinōnia. But there is no real koinōnia between soul and body. This relationship damages the soul, which is forced to transmigrate from one body to the other. Their coexistence is as unpleasant as temporary. And the reason why this koinōnia is fragile resides in the thorough heterogeneity between soul and body, which do not have anything in common. They lack any form of oikeiotēs or syngeneia. Therefore, they cannot form part of a strong koinōnia.

(7a) is a problematic case. To the best of my knowledge, there is no Platonic passage where some kind of syngeneia or oikeiotēs is said to link sensible objects with ideas. There are two possible solutions to this aporia, to my mind. The first one runs as follows. To the extent that all of the “tokens”, so to speak, of a certain “type” share that very “type” (genos), which amounts to the correspondent intelligible form, it is legitimate to maintain that the “tokens” and the “type” are somehow “akin” (syngeneis: i.e. they share the same genos). Sure enough, this willingness to equate intelligible and sensible entities may lead to the notorious “Third Man Argument”.

If this hypothesis falls short of the truth, another option would still be left on the table. Both of the occurrences of the term can be philosophically undermined. The employment of koinōnia in the Phaedo (100d6)³¹ occurs in a context where several terms are tested, in order to efficaciously express the participation-relationship. Hence, koinōnia might be nothing but an unfortunate linguistic attempt, which is echoed only in one passage from the (presumably contemporary) Republic (476a7)³².

(7b) is the most remarkable case. Syngeneia is pervasive across the intelligible world. It grants the latter with strong ontological homogeneity. And what is most important, this fact amounts to the notorious κοινωνία τῶν εἰδῶν³³, which is a pivotal issue in Plato’s philosophy. Both συγγένεια and κοινωνία τῶν εἰδῶν are the condition of possibility of dialectic and philosophy. For, were the εἴδη not to be συγγενεῖς, there wouldn’t be any “communication”, κοινωνία, among them; and were κοινωνία τῶν εἰδῶν not to take place, no λόγος and no philosophy would be possible at all³⁴.

As a mere speculation, one might venture to identify the causal factor responsible for this συγγένεια with the µέγιστον γένος of “being” (ὄν)³⁵. For anything to “be”, an analogous “potentiality to be acted upon or to act” (Sph. 248c5, ἡ τοῦ πάσχειν ἢ δρᾶν... δύναµις) is required³⁶; but in the intelligible realm, to act and to be acted upon amount to “communicating” (κοινωνεῖν) and “being communicated” (κοινωνεῖσθαι)³⁷; and communication and absence of communication entail κοινωνία τῶν εἰδῶν. As a consequence, to the extent that any Form “is”, (1) it participates in “being”, and consequently (2) it turns out to be able to hold, or not to hold, relationships with any other Form. Therefore, “being” grants the intelligible living being with an all-pervasive inner cohesion and with the possibility of koinōnia.

(8) has been already discussed above. I would like to add only a few remarks here. Inter-eidetic συγγένεια (see (7) above) entails the mutual οἰκειότης of those disciplines which form part of the philosophical training of the philosopher-kings in the Republic (537b7-c3)³⁸. Their συγγένεια results from a functional analogy typical of those sciences. All of them are capable of “reorientating” (see µεταστρεπτικῶν ἐπὶ τὴν τοῦ ὄντος θέαν, 525a2) the soul towards the intelligible, thus “waking noesis up” (ἐγερτικὰ τῆς νοήσεως, 524d5)³⁹. Moreover, also ἡ τοῦ ὄντος φύσις and τὰ µαθήµατα exhibit a form of οἰκειότης: and it is the philosopher who should “synoptically” (εἰς σύνοψιν) comprehend this network of onto-epistemological kinship-relationships. More precisely, a set of ontological relationships (the framework of ἡ τοῦ ὄντος φύσις) entails (and is perfectly mirrored by) a set of epistemological kinship-relations across the correspondent disciplines⁴⁰. Hence, as a result of their “kinship”, these sciences exhibit a disciplinary koinōnia.

(11)⁴¹ is perfectly in tune with the analysis conducted so far. Apart from the Menon, where the expression ἅτε γὰρ τῆς φύσεως ἁπάσης συγγενοῦς οὔσης is anything but perspicuous⁴², a form of empirical and horizontal syngeneia, which results into koinōnia, is well attested also in the Statesman, for example (see (2) above). There, people instantiating the same “part” of the “whole” virtue⁴³ are mutually linked by means of immediate kinship-relationships (307d1-4): (T2) “For men who are akin to each class, I imagine, praise some qualities as their own and find fault with those of their opposites as alien to themselves, and thus great enmity arises between them on many grounds” (κατὰ γὰρ οἶµαι τὴν αὑτῶν ἑκατέροις συγγένειαν τὰ µὲν ἐπαινοῦντες ὡς οἰκεῖα σφέτερα, τὰ δὲ τῶν διαφόρων ψέγοντες ὡς ἀλλότρια, πολλὴν εἰς ἔχθραν ἀλλήλοις καὶ πολλῶν πέρι καθίστανται)⁴⁴.

Also (12) requires syngeneia as its condition of possibility. The “kinship” between human beings and the divine is well attested in the dialogues⁴⁵, provided that “divine” is taken to refer to the intelligible. In this sense, there are several passages where this “vertical kinship” is put forward: (T3) “And we must note the things of which it has apprehensions, and the associations for which it yearns, as being itself akin to the divine and the immortal and to eternal being, and so consider what it might be if it followed the gleam unreservedly and were raised by this impulse out of the depths of this sea in which it is now sunk, and were cleansed and scraped free of the rocks and barnacles which, because it now feasts on earth, cling to it in wild profusion of earthy and stony accretion by reason of these feastings that are accounted happy” (καὶ (scil. δεῖ) ἐννοεῖν ὧν ἅπτεται (scil. ἡ ψυχή) καὶ οἵων ἐφίεται ὁµιλιῶν, ὡς συγγενὴς οὖσα τῷ τε θείῳ καὶ ἀθανάτῳ καὶ τῷ ἀεὶ ὄντι, καὶ οἵα ἂν γένοιτο τῷ τοιούτῳ πᾶσα ἐπισποµένη καὶ ὑπὸ ταύτης τῆς ὁρµῆς ἐκκοµισθεῖσα ἐκ τοῦ πόντου ἐν ᾧ νῦν ἐστίν, καὶ περικρουσθεῖσα πέτρας τε καὶ ὄστρεα ἃ νῦν αὐτῇ, ἅτε γῆν ἑστιωµένῃ, γεηρὰ καὶ πετρώδη πολλὰ καὶ ἄγρια περιπέφυκεν ὑπὸ τῶν εὐδαιµόνων λεγοµένων ἑστιάσεων) (R. 611e1-612a3)⁴⁶.

Such kind of συγγένεια is of pivotal importance for several reasons. First of all, this vertical and asymmetric συγγένεια grants the upper dimension of reality (the intelligible) and the lower one (human nous) with some form of “communication” (koinōnia). They are put in touch by means of συγγένεια, thus granting reality as a whole with inner cohesion.

Moreover, without an ontological homogeneity between the soul and the intelligible, no prenatal acquaintance with the ideas would have ever been possible for the disembodied soul; and were that prenatal “event” not to have occurred, no knowledge at all would have been possible for the embodied soul. In other words, this asymmetric συγγένεια is the condition of possibility of the prenatal vision of the Forms, which is in its turn the condition of possibility of everyday knowledge⁴⁷. As a matter of fact, the cruciality of this theory would be better appreciated if one considered the paralyzing potential inherent to Menon’s paradox. The essential continuity between the soul and the intelligible can be damaged (and it is damaged, when the soul is embodied), but it can never be thoroughly erased. Thus, intellectual enquiry and noetic cognition always turn out to be possible. And Menon’s paradox is neutralized once and for all⁴⁸.

Last but not least, along with a “dialogic communion” (13), also a “dialogic kinship” can be found at work in the dialogues. In the Statesman (257d1-258a1), for example, we are explicitly told that only logoi can make real syngeneia among people come to the fore: (T4) “And besides, Stranger, it seems to me that they are both related to me after a fashion; one of them anyhow, as you say, looks like me in his cast of countenance, and the other has the same name and appellation, which implies some sort of kinship. Of course we ought always to be eager to get acquainted with our relatives by debating with them (Καὶ µὴν κινδυνεύετον, ὦ ξένε, ἄµφω ποθὲν ἐµοὶ συγγένειαν ἔχειν τινά. τὸν µέν γε οὖν ὑµεῖς κατὰ τὴν τοῦ προσώπου φύσιν ὅµοιον ἐµοὶ φαίνεσθαί φατε, τοῦ δ’ ἡµῖν ἡ κλῆσις ὁµώνυµος οὖσα καὶ ἡ πρόσρησις παρέχεταί τινα οἰκειότητα. δεῖ δὴ τούς γε συγγενεῖς ἡµᾶς ἀεὶ προθύµως διὰ λόγων ἀναγνωρίζειν)⁴⁹ .

Actually, Socrates does not claim that for a “dialogic communion” (koinōnia) to take place something like a previous “kinship” among the interlocutors is required. He only maintains that logoi represent the legitimate means whereby an already existing, profound kinship among the discussants can be shown. But in the dialogues, there are some traces of a form of syngeneia that “horizontally” equates people, thus enabling them to intellectually (and hence also dialectically) interact with one another. Each individual nous is συγγενής, “akin”, to any other nous. Each of them belongs to the same “genre” (genos): hence, all of them are closely “akin” (syngeneis). Thus, human beings happen to be bound together in a fully natural way, by means of a “horizontal” and “noetic” συγγένεια. In other words, men are naturally “akin”, in as much as they are all somehow “demonic”⁵⁰.

III.

Let’s now draw some brief conclusions. As I have sketched out above in the abstract, Plato’s ontology seems to largely employ the couple koinōnia/syngeneia. But also, political communities intrinsically draw upon the complex web of kinship-relationships that bring people together, that make them koinoneisthai. What’s more, even Plato’s epistemology is somehow grounded on “communication” and “kinship”. Actually, it is philosophy as a whole, in as much as it entails the koinoneisthai among its adherents, that requires some form of pre-existing syngeneia. In other words, Plato’s philosophy cannot but deal with this fortunate couple precisely because it owes to them its very existence.