The Propedeutic of the Theory of Judgment in Ancient Philosophy From the Sophists to Plato’s Theaetetus

Abstrakt: W epistemologii starożytnej ściśle sprecyzowana definicja sądu (axioma) pojawia się dopiero w III wieku p.n.e., sformułowana przez Chryzyppa z Soloi, twórcę logiki stoic kiej. Analiza postaci wypowiedzi, w jakich obiektywizowała się wiedza od czasów pierwszych greckich myślicieli pozwala stwierdzić, iż kształtowanie się teorii sądu było długim procesem. W procesie tym epistemologia grecka musiała rozwiązać szereg problemów związanych zarówno z przedmiotem sądu — wiedzą, jak i z samą postacią jej obiektywizacji — orzekaniem, jak też z predykatami sądu prawdziwego i fałszywego — z kategoriami „prawdy” (aletheia) i „fałszu” (pseudos). Pierwszą definicję sądu fałszywego (logos pseudes) i sądu prawdziwego (logos alethes) odnajdujemy dopiero w późnym platońskim dialogu Sofista, który przynosi nam już w dużej mierze uporządkowaną terminologię teoriopoznawczą. Taka definicja mogła jednak być sformułowana dopiero wtedy, gdy epistemologia grecka zredefiniowała znaczenie pojęć/terminów aletheia i pseudos. Termin/pojęcie aletheia był tożsamy z terminem/pojęciem bytu, funkcjonując w obszarze ontologiczno-aksjologicznym, zaś pseudos nie oznaczał fałszu w znaczeniu: zaprzeczenia prawdy, lecz coś od niej różnego. Filozofia przedplatońska nie wykształciła jeszcze terminologii, w której można by przekazać orzekanie o czymś niezgodne ze stanem faktycznym — z prawdą. Często dla określenia takiej postaci orzekania stosowano termin: „mówić niebyty” (things which are not). Kolejny problem wynikał z właściwej językowi greckiemu podwójnej funkcji czasownika być/einai, która jednoczyła w sobie funkcję egzystencjalną i prawdziwościową. Zgodnie z tym każda postać wypowiedzi, w której funkcję orzeczenia pełnił czasownik einai lub jego derywaty ex definitione była orzekaniem prawdziwym — „Folia Philosophica”. Vol. 42, s. 21—45 Katowice 2019 ISSN 2353-9445 (online)

Słowa klucze: sąd, logos, prawda/aletheia, fałsz/pseudos, mniemanie/doksa, referencyjna funkcja języka, predykatywna funkcja języka In ancient epistemology -in those texts that have survived to the present day -the first precisely formulated definition of a judgment, called an aksioma, can be found in the philosophy of the Old Stoa; as Diogenes Laertius relays, it is the work of Chrysippus, 1 the founder of Stoic logic. In this definition, Chrysippus concentrates on its formal and logical aspect, distinguishing a judgment from such utterances as statements, commands, conditional statements, and all statements of emotive nature. According to Chrysippus's definition, a judgment is a full statement 2 preceded by an act of the will 3 (pragma autoteles), which results from predicating of something in the form of a full sentence that can in itself be confirmed or denied and may thus be true (aksioma alethes) or false (aksioma pseudos). 4 Knowledge -the product of cognitive procedures -is objectified in such judgments. The most important criterion distinguishing a judgment from other types of statements is that a judgment may be true or false.
It is interesting to consider why, after Greek thought had already been developing for centuries, it took until the time of the Stoic School to work out a formal definition of a judgment. Of course, we cannot exclude the possibility that such a definition was formulated in older philosophical texts which did not survive to our times. However, an analysis of the forms in which knowledge was objectified from the time of archaic philosophers shows that the Old Stoa's definition constitutes a kind of a summary of the long process of formation of the theory of judgment. In this process, Greek thought solved many problems connected both with the object of judgment -knowledge and its object -and with the form of judgment itself -predication, with the necessity of answering the question of whether language -words -logos can reveal the nature of reality, and whether it is possible to predicate of that reality in a way that is inconsistent with its nature, and finally with the problem of "truth" (aletheia) and "falsehood" (pseudos) as predicates of the form of predication. Moreover, on the long path to working out a definition of judgment, it was only Plato in his late dialogue Sophist who precisely established the terminology connected with this definition -in pre-Platonic philosophy, and in Platonic philosophy's Socratic and Middle Academy writings, it is often difficult to determine whether the term λόγος is meant in the sense of story, statement, dialectic procedure, judgment, or simply as "word." It is therefore worth taking a brief look at the prehistory of the theory of judgment, starting with the beginnings of Greek thought up to the time of Plato's dialogue Theaetetus. This area of research may be justified by the fact that Theaetetus occupies a special place in Plato's opus. An attempt has been made to demonstrate that this dialogue, on the one hand, serves as a summary of the Platonic critique of the theory of ideas described in the dialogue Parmenides, and on the other, as a preface to the next stage of development of Platonic thought, which can be seen in Sophist. Moreover, in Theaetetus we can find the proper propedeutic of the theory of judgment in a strict sense, with the indication that the object of judgment is knowledge of being.
We must begin by attempting to answer the question of whether, in light of the meaning of the terms-categories aletheia and pseudos, in the beginnings of Greek thought, a formula defining and differentiating the form of predication through use of the criterion of truth and falsehood -by attributing the predicate of alethes or pseudos to the predication (logos, doxa) -could have been created.
We can accept that the first Greek forms of predicating of the nature of reality, 5 formulated by the first philosophers in the form of lectures (logoi), laid claim to truth through the form of the utterance itself. Particular visions of reality -the nature of fysis, which appear in the conclusions of those fysikoi, can be reduced to the form of judgments supported by a line of argument to which may be attributed a predicate of truth or falsehood. We must remember that such procedures, which we necessarily undertake in research on the oldest Greek thought, are part of our modern research methods. However, they can be compared to attempts at including in the specific pattern of philosophizing thinkers who, in fact, philosophized completely differently and objectified their research results differently. Meanwhile, the form of predication on nature was largely determined by the structure of the Greek language available to the first philosophers, and above all, the function and role of the verb einai and its derivatives. 6 Of the many functions of this verb, two come to the fore, which can be described as the existential function and the truth function. This verb and all its derivatives (especially participles: on, adverbs: ontos, substantives: to on, he ousia) unite two functions of language in their application (in colloquial speech, in poetic language, and in philosophical language): the referential function, when in the act of predication we identify the object we are predicating of; and the predicative function, when we express what we want to say about the predicated object. For, in the act of predication, we are saying something about something. Before the act of predication is formulated, the object of predication must be distinguished, regardless of whether it is an object with objective or subjective being, or even the language itself -its rules or form of expression. This act of distinguishing each object of predication -its identification -is carried out through the referential function of language, which in philosophical predication, or in the philosopher's understanding of 25 this act of predication, gives the object an ontic status. In turn, we predicate something of this object -here, the predicative function of language is realized. The act of predication is -or at least should be -understood by the recipient of the message. Therefore, the referential and predicative functions of language are also realized in the process of understanding the form of communication that is predication. For if we predicate of something that it is (resp. exists), we identify the object of the predication as being (resp. existing) -as an entity -and we attribute to it simultaneously being in general, being in some place, time, space, or state. All forms of indicative sentences in which the function of a predicate is fulfilled by the verb einai or its derivatives can be reduced to such an existential judgment; in Sophist, 7 Plato extends this to all indicative sentences in which the predicate, expressed using any verb, can be transformed in such a way that a form of the verb einai appears (e.g. "Theaetetus flies," which should be understood as: "There is the flying Theaetetus," or: "Theaetetus is flying," etc.). In pre-sophistic philosophy, this fact determines the form of predication with an absolute claim to truth about all reality, a predication that presents this reality as it is, not as it appears to those who opine. In such predication, still far from the form of judgment that appears in Plato and is later precisely defined by the Stoics, the truth of the predication is contained in the formula of the utterance itself -with the predicate in the form of the verb einai, as well as in its modality -it is always an utterance in the indicative mood.
Long before Protagoras ordered Greek grammar, distinguishing and naming modes, the Greeks realized that sentences in the indicative mood express categorical statements. 8 If the verb einai served as a predicate in such sentences, these sentences were true by definition, while the verb in a double -referential and predicative -function determined both the 7 Plato: Sophist 263a ff. 8 Language as a system that updates itself in specific acts of speech and is subject to specific rules, and language as a system of signs existed and functioned for centuries before the emergence of rational thought, and all rules and laws governing it functioned efficiently long before the emergence of the first grammar textbook in the history of Western culture written by the sophist Protagoras and the first semiotic directives that appeared in the writings of the sophist Prodicus. The basis of that first grammar must have been careful observation and comparative analysis of many specific acts of speech-messages, especially the relationships between certain forms of messages and verbal modalities. The conclusions of these observations -distinguishing and naming verb modes and assigning them to specific forms of utterances -were an accurate reproduction of the rules governing acts of speech and transferring them to the structure of the language as such. The author of the first grammar therefore put into the rules those language phenomena that had in practice functioned since the inception of language as a tool of communication.
fact of the existence of the object of which it predicated and the truth of the given predication. In addition, this verb determined the stability and immutability of the object of which it predicated. An expression of this are the oppositions that appear in pre-sophistic philosophy: einai-gignesthai, which reflects the main theses of the Heraclitean vision of the structure of reality, as well as the oppositions: einai-phainesthai-doxazesthai (to seem, to believe that something is) reflecting the Parmenidean notion of being. Therefore, each predicating statement with a predicate in the form of the verb einai was, in pre-sophistic philosophy, in intention and by definition a true statement -it "said things which are," regardless of how every philosopher conceived of being. We can thus venture the claim that the earliest Greek philosophers did not need the category of aletheia in the epistemological sphere, or the desideratum of "telling the truth" (aletheian legein, ta alethe legein), or truth as the predicate of a statement (alethes, alethinos). This thesis is confirmed by an analysis of the terms aletheia, alethinos, alethes and their derivatives in the extant fragments of the writings of pre-sophistic philosophers, and of the contexts in which they appear. The findings of such an analysis allow us to conclude that the category of aletheia -truth in the most ancient Greek thought -appears in the ontological and axiological aspect: aletheia/truth is an attribute of being, regardless of what the thinker recognized as being. True being is real being, therefore truth is identical with being in these contexts, and as an attribute it cannot be granted to what is not being, as well as to suchsupposed -forms of being that appear to people as a result of wrong methods of viewing nature: the result of opinion (doxai) or succumbing to illusion (apate). In turn, an analysis of the contexts in which the category of pseudos appears, which is usually mistakenly translated as "false," thus obscuring its proper meaning in the texts of pre-Sophistic philosophers, allows us to state that it does not appear as an antithesis to aletheia/truth. Pseudos means something that differs from the truth in the sense of: less perfect, worse, or less a being, e.g. an image and its copy. 9 The functioning of this category in the ontological and axiological sphere, however, inspired philosophical disputes which began during the 9 For more on this subject, cf. J. Gajda: Przedplatońskie koncepcje prawdy. Ontologiczny i aksjologiczny aspekt kategorii ἀλήθεια w filozofii przedplatońskiej. In: Studia z filozofii starożytnej III, Filozofia XIX. Ed. J. Gajda. Wrocław 1993, pp. 30-52. This meaning of the term pseudos is still found in Plato's Middle Academy writings, when the Philosopher, e.g. in the Republic (414b ff.) recommends passing paideutic content to the people not in the form of lectures -strict argumentation, but through ta gennaiapseude, i.e. in the form of a myth. Cf Athenian Enlightenment, about whether it is possible to predicate something differently than it is -falsely -that is, about whether it is possible to "say things which are not." 10 In extant texts, this phrase appears with at least several different connotations. We will necessarily focus on one of the meanings: to speak (predicate) not as it is, i.e. not in accordance with the "truth of things." 11 Until the time of the sophists, specifically until the time when two works by Protagoras appeared: On Being (Peritouontos) and Truth (Aletheia), 12 Greek philosophy did not know the form of a judgment at all, and it can be assumed that this did not present a problem for it. Protagoras accepted that the predicate of being in Parmenides's understanding could not be attributed to perceived things, states, or phenomena -those chremata with which humans come into cognitive/intellectual contact. However, we cannot predicate other, sensually-imperceptible forms of reality, such as the gods or the arche/principle that determines one necessary and subordinate order 10 For a more in-depth discussion of this issue, cf. J. Gajda-Krynicka: Czy można 'mówić niebyty'. Koncepcja sądu fałszywego w 'Sofiście' jako przewrót epistemologiczny w filozofii greckiej. In: Kolokwia Platońskie, Parmenides. Sofista. Ed. M. Manikowski. Wrocław 2003, pp. 101-137. 11 Other connotations of this phrase include: 1) predicating something that "is" not (ouk esti) -i.e. non-being -like Parmenides of Elea, who of course excludes this possibility, because non-being "is not and cannot be," and you cannot predicate what is not; 2) to speak (predicate) of something that does not exist, distinguishing the existence of being from the existence of "things" [ta pragmata, ta chremata] (such as Chimera, the sea-faring chariot, or a flying man) -like Gorgias of Leontini (Diels FVS Gorgias B 3), who in his critique of Parmenides's ontology presented in the work On Non-being or on Nature admits such a possibility; moreover, he accepts, contrary to Parmenides, that what is not -Parmenidean non-being, or non-existent things, can be the object of thought and predication, such as things that never happened (Helen's fault, the betrayal of Palamedes), or some first principles-archai dreamed up by physicists (meteorologists); 3) to speak about states or phenomena that do not actually exist but appear to people as existing, e.g. about coming into being/birth or perishing/death: when we talk about coming into being or perishing, we say "non-being" because, as Empedocles (Diels FVS Empedocles B 8, 4) or Anaxagoras (Diels FVS Anaxagoras B 17, 4) write, there is neither ex nihilo coming into being nor perishing into nothingness, a notion unknown to Greek philosophy; coming into being is the mixing of always-present elements, and dying is essentially the disintegration of a thing, state, or phenomenon into its original elements; so when we speak of birth or death, we speak "things which are not." 12 This is reconstructed mainly on the basis of Plato's Theaetetus (152 ff.); from this work comes Protagoras's famous statement: "Man is the measure of all things, of the things that are that they are and of the things that are not that they are not"; however, this statement does not refer to the categories of being and non-being, but to the qualities of specific chremata (cf. J. Gajda: Sofiści. Warszawa 1989, p. 100 ff.). of reality, because we are limited in our attempts to reach them. 13 On the other hand, these chremata are subject to constant changes, coming about and perishing, mutual mixing and relationships. Therefore, the only source of cognition are the senses, providing individual and subjective perceptions, different to each perceiving subject; moreover, these perceptions change depending on the state of the perceiving subject: his/her health, illness, and sleep-or waking-state. 14 Thus, Protagoras accepts that every perception is true, even when each of e.g. two cognitive subjects perceives the same thing differently. Protagoras is speaking about a statement (logos) about something. I think that the sophist, who, after all, wrote the first Greek grammar, distinguishing and naming modes, and formulating the verb modalities according to strict rules, assumed that a statement about something must be formulated in the form of a sentence in which the predicate is always in the indicative mode. We can consider this a prototype of the definition of a judgment, although Protagoras's notion of isostheneia -the equal strength of judgments -results, unlike in the later skeptical philosophy, rather from the helplessness of the sophist in the face of the question of whether it is possible to "say things which are not," than from specific methodological and epistemological findings. In addition, the traditional attribution of familiarity with, or even formulation of, a theory of judgment by the sophist is questionable. 15 Protagoras talks about a statement (logos) about something, but a statement-logos is not yet a judgment-logos. In light of Plato's Theaetetus, one should rather assume that Protagoras speaks of the equal strength of objectified opinions -doxai, which cannot be judgments, because they are only axiologically, not epistemologically, verifiable. Moreover, Protagoras's formula does not concern knowledge, but sensations, i.e. what appears to man (phainesthai) in a sensory view. We may consider this a prototype of the definition of a judgment, although in the scant legacy of the philosopher from Abdera this definition has not survived to our time and still raises many doubts. However, regardless of whether we consider Protagoras's form of predicational pre-definition of a judgment or not, there is no doubt that, according to the sophist, false judgments cannot be formulated, because there is no criterion of truthfulness of expression, which was expressed in the formula ouk esti antilegein.
It is Gorgias of Leontini, almost a contemporary of Plato's, who for the first time in Greek philosophy writes about "true" (correct, proper) statements, in which knowledge of facts is objectified, flowing from both experience and logical procedures, and incorrect statements, resulting from ignorance, submission to opinion, and ill will, in two extant epideictic speeches: Encomium of Helen 16 and Defense of Palamedes. 17 In these speeches, the sophist from Leontini uses the terms aletheia and pseudos from a gnoseological perspective: "truth" and lie/falsehood as features of speech-logos, 18 which are set in opposition to one another for the first time in ancient philosophy. In Encomium of Helen, which the sophist himself describes as a joke (paignion), 19 he attempts to free from infamy the character known to all Hellenes, demonstrating on the basis of "logical reasoning" (logismos) that the widespread belief in Helen's guilt is based on the messages of poets, and they are not true, because they use the power of the word (logos) to shape opinions (doxai) that are not true. It is man's duty to strive for truth and expose falsehood. Nevertheless, the sophist in Encomium of Helen also uses the term logos to define all utterances, including epic poems; court, political, or epideictic speeches; and the treatises of natural philosophers, whom he calls "meteorologists." It is not until the Defense of Palamedes that we find the first attempt at defining logos as a judgment. In it, the sophist presents a speech apparently made by a mythical hero in his own defense after Odysseus had wrongly accused him of treason against the Greeks and of scheming for the Trojans during the siege of Troy. The listeners of the sophist knew the tragic fate of Palamedes 20 -so they knew perfectly well who "speaks the truth": the accuser Odysseus, out of a desire to take revenge, lies, uttering a false judgment about the non-existent fact of betrayal, while innocent Palamedes, claiming that the fact of betrayal did not exist, utters a true judgment. In this speech of Gorgias, we find an interesting epistemological situation created: Palamedes gives his apology before the judges (earlier, as you can guess, Odysseus made his accusation). Therefore, the judges, because of the function they perform, are faced with the necessity of recognizing as true one of two opposing statements/judgments 21 without knowing the facts, and their decision will have important consequences. Here, the sophist formulates a kind of cautionary tale related to the necessity of often ruling about what we have not experienced in life -for the judges took the accuser's statement/judgment as true, condemning the innocent Palamedes to death, thus committing an irreversible mistake. 22 We can therefore accept that in Gorgias of Leontini we already find articulated the concept of a judgment. It is a statement that can be true, i.e. consistent with what has occurred, or false -inconsistent with the facts. Thus, the category of pseudos takes on the meaning of the opposite of truth/ aletheia, setting itself in the realm of epistemology sensu stricto. For the sophist, a false statement is made when the one who formulates it either does not know the facts, because s/he did not see them, did not participate in them, or does not know them from a reliable source, or when the person formulating the statement deliberately distorts these facts. Thus, it is possible to predicate falsely. For Gorgias, judgments-logoi only refer to facts; they only reveal the truth or falsehood of words and actions (aletheia ton ergon kai logon), 23 and do not refer to the truth of being or truth of the cosmos (aletheia tou ontos, aletheia tou kosmou).
As mentioned above, the opposition: aletheia-pseudos did not appear in Greek philosophy until Gorgias. In pre-sophist philosophy, and even in those dialogues of Plato's that were written before Sophist, the antithesis: truth-falsehood (on the grounds of epistemology), where one speaks of the form of utterances, predication, or the original form of judgment, has 21 The drama of the situation is compounded by the fact that recognizing one of two statements/judgments as true will result in either condemning an innocent person to death or releasing him from the charges, as the protagonist himself explicitly states (Diels: FVS Gorgias 11a, 226). 22 A question arises here: what statement/judgment would the sophist Protagoras accept, with his concept of the equal strength of judgments? For the sophist of Abdera, in view of the necessity of adopting a judgment, the deciding factor was whether acknowledgement of a particular judgment would benefit not so much an individual as a group of citizens. In the light of this conception, Protagoras would certainly conclude that Odysseus's judgment should be accepted, due to his future merits for the Greeks in the Trojan War -Palamedes's accomplishments, his inventions for the sake of the Hellenes, took place in the past. 23 Diels FVS Gorgias B 11a 226. the form: "to speak being" [ta onta legein] (resp. to say what is and how it is) -"to speak non-being" [ta me onta legein] (resp. to say what is not and not as it is). Accordingly, the predicate einai cannot be attributed to what is not (resp. does not exist), and therefore it is impossible to speak nonbeing -ouk esti ta me onta legein. Apart from the sophists, the philosopher chronologically closest to Plato who accepted that ouk esti ta me onta legein was Antisthenes, a student of Socrates and the sophist Protagoras. 24 Antisthenes's argument about the impossibility of false predication can be reduced to the following form: when someone says something, s/he says something that is, i.e. is a being, or has being, understood as "something that is something beyond everything else," hence s/he speaks being (to on legei); if s/he speaks being, in turn, then s/he speaks truth. However, one cannot say what is not or what is not a being, because in the act of linguistic reference one cannot distinguish something that is not as a point of reference (ouk esti ta me onta legein), as what is not cannot be transformed into what is. No one speaks about non-being -thus no one tells the "untruth" (resp. predicates falsely). Every predicating statement is also true because Antisthenes assumes that every thing or state of affairs (pragma) has its verbal expression (logos) in the form of predicating on what it is or is not. Therefore, each term can be assigned to a specific state. If the object of the term was something that is not, there would be a basic contradiction: such a term could not be formulated, because the rule that every thing (pragma) has its own definition (logos) cannot be reversed; for not every term has a corresponding thing, not every name belongs to its referent, as Gorgias writes in the treatise On Nature or on  For Antisthenes, every statement (logos) has its own object, it "says things which are," and therefore each is true. 26  Antisthenes could have assumed such a relationship between the name and its referent, because he claimed that only individual things perceived sensually exist, and general concepts are in fact only names that in the order of existence are post res; no nameword description -could come about if it did not have a referent. Antisthenes's belief that "you cannot speak non-being" also derives from the fact that one can only predicate of individual things tautologically -that they are, and that they are as they are. They cannot be defined per genus proximum et differentiam specificam; all attempts at defining things are only "a long accumulation of words." Tautological prediction, on the other hand, must always be true. are not." In this dialogue arise problems which are not solved until Sophist. These can be reduced to the question: can the truth of being (aletheia ton onton) be reflected in a statement -in the logos (in this dialogue, Plato does not yet use the term logos in the sense of "judgment")? After all, we remember that the philosopher often expressed this "truth of being" in a myth, 27 can it also be expressed in the logos?
I think we can venture to say that Plato, in his search for the form of being that "truly is," on his way, first to the conception of ideas, then to the conception of principles, is simultaneously looking for tools to predicate of such being. In Meno, the first text, chronologically, in which the theory of ideas is outlined, the category alethes appears for the first time, but it is not used to describe proper judgment, which the philosopher describes using the predicate orthos 28 -meaning right, proper; instead, Plato uses it to describe opinion (doksa). What are "true opinions" for Plato? They may be understood as such results of sensory perception (aisthesis) that reveal the perceived object as it is, without deforming it, 29 as well as revealing some type of unity in the dispersed multiplicity of things and phenomena, even if it is solely in the intellectual joining into sets of genera and species. Only the opinion that, as Plato later says in Phaedrus, 30 can bring the multitude of perceptions "kata mian idean," which can distinguish, for example, appearance, deception, or illusion of good from the real good, if only in deeds and actions, deserves the name of "true opinion." "True opinions" can be the basis for formulating right or correct judgments, but are not identical to knowledge. Although right judgments, based on true opinions, can be a source of good and proper conduct, they have impermanent and shortlived power and encompass only a limited set of goods in the phenomenal world, as they lack reference to the form of true being. A correct judgment cannot therefore be synonymous with knowledge.
Let us return to the dialogue Euthydemus. In this text, Plato deals with two opponents, as it were: with Antisthenes and his conviction that oukesti ta me onta legein, and with the sophists, who base their belief that they are never mistaken because they know everything on Antisthenes's thesis. They 27 Cf. Gorgias 523 ff., Phaedrus 245C ff., 274C ff. 28 Plato: Meno 97b-c ff.; the Polish translation of Meno authored by W. Witwicki translates the term: orthos as "true," which may cause confusion; it should be translated as "right" or "correct." 29 Since the time of Xenophanes of Colophon, the term opinion (doxa) functioned as the opposite of knowledge, cf. Diels FVS Xenophanes B 35; for Parmenides, "mortal opinions," resulting from fallible sensory perception, were the opposite of truth in its ontic aspect, in the sphere of predicating of being. 30 Plato: Phaedrus 265d.
base their arguments on tortuous dialectic, according to which "knowing anything means knowing everything," because you cannot be both knowing and unknowing at the same time, and what is not an object of knowledge, i.e. predicating with a claim to truth, does not exist. 31 Euthydemus, the sophist, completes this argument by identifying speaking with action and doing something -you cannot do what is not, action must always have an object; thus, no one says what is not -ta me onta, or untruth. 32 The sophists' dialectic is admittedly based on the assumption that ouk esti ta me onta legein, but without the ontological validation present in Antisthenes. It essentially consists of juggling the meaning of words. 33 The sophists have two opponents in the dialogue: the common-sensical Ktesippos, who demands verification of their knowledge with the actual state of affairs, 34 and Socrates. Socrates is able to refute the thesis of the sophists by referring to their profession: teaching virtue -arete. Since you cannot speak untruths, you cannot remain in the power of erroneous beliefs, and thus you cannot be wrong in your actions. Therefore, everyone knows how to act and has no need for the sophists' teachings. But Socrates's arguments are also largely common-sensical -he fights the sophists with their own weapons, because in this dialogue Plato is not yet able to free himself from the pre-Platonic understanding of the relationship between truth and being, and falsehood and non-being. It is not until Cratylus that we perceive the first such attempts, though the problem of whether false statements can be formulated is not the main subject of the dialogue. In it, we find the question of whether it is possible to utter false (pseudes) sentences (logoi) 35 ; therefore, the predicate of falsehood (pseudes) was assigned by Plato for the first time in philosophy to statements-predication. The answer to this question is a kind of prototype 31 Plato: Euthydemus 293a, 294c. 32 Ibid., 283c-284d; the sophists' tortuous dialectic is based on the belief that the relationship between pragma and logos is two-sided, which is already criticized by Gorgias; for Euthydemus and Dionysodorus, everything has a name, which means that each name has a referent; this conviction is not only the domain of "subversive sophistry," as we also find it in many writings of the so-called Corpus Hippocrateum, such as the statement that there must be medical art (techne iatrike), because it has a name. 33 Ibid., 292d ff.; in specially and wittily selected examples, Plato's Socrates demonstrates the uselessness and harmfulness of sophist dialectic, which can at most show that Ktesippos is the brother of his puppies; that the happiest person is one who swallows three gold talents; and the father gods can be sold or donated to anyone. 34 Ibid., 294b: "No, do not say that, he replied: only tell us this one thing more, and propound to us that you speak the truth. Then, if you tell us how many teeth each of you has, and you are found by our counting to have known it, we shall believe you thenceforth in everything else likewise." 35 Plato: Cratylus 385b, 429d.
of the definition of false judgment later formulated in Sophist: thus, [the statement] that would predicate of entities that they are, is true, while the one that would predicate of entities that they are not, is false. 36 But in Cratylus, Plato is still examining the truthfulness of names (onomata), 37 or more precisely, trying to answer the question of whether examining names will allow us to reach the essence of the thing named with a given name. Plato states in Cratylus that a name can express an object, as long as it is a sign and an image of the object. There is no doubt that a name has a different ontic status than the named object: the name is not an object. At the same time, names are not completely separate from things -a name is somehow related to the thing it names. The form of this relationship is defined by a concept well-known since Homeric times, or even earlier -the concept of a sign: a name-sign refers to things. Plato specifies the form of this relationship -he calls it an imitation and image. A name expresses and refers, because it is an image of things. For Plato, imitation does not signify a faithful copy in all the smallest details. It would be more precise to talk about a reflection or reproduction, which inevitably has a different ontic status and a different -lesser -value than the original. In the case of a word -sign-name -the sound, the composition of phonemes imitates the structure of things that determines their essence. 38 A name relates to things in the same way that, in the light of Plato's later teachings, a phenomenon relates to ideas. Therefore, the question about the truthfulness of names will not receive a positive answer. A name cannot be true (alethes); as an image or imitation it has less of the truth of being in itself. One can venture to say that in Plato's text, it is not written that names are "false" in the sense of the term pseudes defined above. As such, they cannot be a sufficient source for coming to know a thing as such, called by a specific name, but they are the only tool given to us to communicate and convey thoughts. For Plato, language is necessarily a tool for giving meaning and objectification. As such, it is subject to evaluation. Its proper use consists in expressing things as they are, in order to formulate statements which later in Sophist 38 Plato writes critically about the category of mimesis in Books III and X of the Republic: distinguishing the degrees of imitation (the idea of a bed, encompassing the essence of a bed; individual beds made by craftsmen modeled on the idea of a bed as an imitation of the first degree; the image or form of a bed, modeled on the bed made by a craftsman; the latter is further away from the idea). view, in Plato's later writings the problem of the origins of language and of language signs, the proper subject of the dialogue Cratylus, fades into the background. Of course -as the philosopher writes in Cratylus 39 -it would be incomparably easier if there was an ideal language, if words faithfully reflected the essence of things. But such a language does not exist, most likely never existed, and will never exist. Therefore, the philosopher must use the existing language, common to all and belonging to all, as a tool for expressing his/her thoughts, objectifying experience, and for communication. A philosopher can improve this tool; s/he can make language a tool of truth, because names and sentences are signs, because language as such is a system of signs that refer to something. Even if a name or sentence refers to non-being, according to Plato it is no longer a reference to non-existence, as it is for Parmenides. The non-being to which the name or sentence refers, in which we predicate of non-being, is not Parmenidean non-being, but something different (thateron) from being. But language does not only serve the truth: the same language signs that serve the philosopher to predicate truly serve other masters of the word -sophists or speakers, those inept imitators, who do not know what they are imitating -to make false statements, and create inept images and imitations. Thus, these language signs are a double-edged sword that is easily misused; so nothing remains other than to place language in the service of truth -to follow certain rules of usage to language signs: to predicate what is, how it is. What is more, the role of the philosopher who seeks the truth of being is to unmask and reveal the errors or dishonesty of those who, unknowingly or intentionally, for benefits or for power, remaining in the conviction that it is impossible to "speak things which are not," speak what is not with a claim to absolute truth, based -paradoxically -on the belief that no one can say what is not. Although names-language signs understood this way do not reveal the essence of things, merely referring to them, they can be a tool of communication, predication, they can express thoughts. It is not without regret that Plato states that even philosophers cannot use language as a system of signs: if a philosopher wants to convey his/her knowledge, his/her truth in a comprehensible way, s/he must follow the rules governing the language of the community in which s/he lives. In Sophist, Plato confirms the arrangements contained in Cratylus: language and thought are of the same nature, because both are logos-statements, which consist in the proper arrangement and combining of signs-names. 40 The whole language is a system of signs. Names and sentences function as signs in the semiotic situation determined by the communication, because they refer to something: to things as such, to ideas, to the essence, to concepts, or to states of the soul. Can they, however, refer to non-being? Therefore, the eternal question of pre-Platonic philosophy returns: can one speak non-being? Is a false statement/judgment possible? Can such a statement possess a logical value?
This problem will be definitively solved by Plato in Sophist, but a kind of propedeutic of the definition of false judgment formulated in this dialogue (logos pseudes) can be found in Theaetetus.
I view Plato's Theaetetus as a constructive dialogue, pertaining to the epistemological and methodological dimension of Platonic thought, and this is due to the fact that he undertakes a problem that is important not only for his own conception, but for the whole of Greek philosophy: what is knowledge? However, he examines it not so much with a view towards the object of knowledge and its strict definition, but rather due to the form of its objectification, i.e. judgment-logos, as well as the form of its verification through dialectical procedures, which Plato also describes as the logos.
Both in the relative chronology of Plato's writings and in the sequence of stages of the philosopher's development, Plato's Theaetetus must occupy a place between Parmenides and Sophist, in which we find -for the first time in Greek philosophy -an articulated definition of a judgmenta false judgment and a true judgment. 41 The dialogue Theaetetus is therefore propedeutic; it shows us Plato's struggles and work on a clear and precise definition of a judgment-logos, understood both as the objectification of knowledge, i.e. statements (or a set of statements) predicating of some object with an absolute claim to truth, as well as establishing the rules to which this statement should be subject, and the research procedures enabling the formulation of such a statement. 42 It seems obvious to us that knowledge, regardless of its object, can only be objectified in a judgment -true logos -that fulfills the criteria of truth. Its opposite can only be a false judgment. Such a view is not accepted and defined by Plato until the dialogue Sophist, in which the categories: truth/truthfulness -aletheia, alethes, as well as false/falsehood -pseudos, pseudes, acquire new meaning, having been transferred from the realm of ontology and metaphysics to that of epistemology and methodology. In Sophist, Plato uses already precisely developed epistemological terminology, formulating for the first time in the history of philosophy the definition of the truth of the judgment, as well as the criterion of that truth. Nevertheless, there is no doubt that the development of this terminology required a prolonged effort -long dialectical procedures, so vividly illustrated by the author of the autobiographical Seventh Letter that has been attributed to Plato. Therefore, I accept that the dialogue Theaetetus shows us the philosopher's work on the notion and theory of judgment, these preliminary preparations preceding the articulation of the theory in Sophist.
There can be no doubt that all attempts at studying and analyzing Plato's Theaetetus in isolation from other Platonic writings, i.e. without the context imposed by relative chronology, must lead to the conclusion that it is not a constructive work -that it is a purely aporetic dialogue and does not bring solutions or answers to the question formulated at the beginning of the letter: what is knowledge-episteme? 43 However, if we set it within the relative chronology of Platonic writings before the dialogue Sophist 44 and after the dialogue Parmenides, I think we can find in it both positive solutions in the form of the propedeutic of the theory of judgment that appears in Sophist, as well as an explanation of why Plato cannot yet answer the declarative question of the dialogue concerning what knowledge is.
What justifies attempts at situating Theaetetus in relative chronology after the dialogue Parmenides, considering all the latter's criticism of the form of the theory of ideas that Plato adopted during the time of the Middle Academy? Two significant premises point to this. First of all, the fact that in Theaetetus there are no references to the Middle Academy theory of ideas, either concerning their ontic status -as the first beings in ordine essendi -or in regard to their relationship with things. This is demonstrated (among other things) by the fact that Socrates emphasizes that it is not the object of knowledge that is being reflected on, but knowledge itself 45 ; if we cite the dialogue Phaedrus, we will see that for Plato during the Middle Academy period, the object of knowledge identical with 43 Plato: Theaetetus 145e, 146a. 44 Cf. Plato: Sophist 216a; I do not, of course, consider the declarative reference at the beginning of Sophist to Socrates's supposed discussion with Theaetetus and Theodore the previous day as decisive in regard to the relative chronology of Theaetetus; a similar reference can be found in Timaeus, which refers to the "previous day," when the discussion about the perfect regime of the Republic apparently took place. However, this is a kind of sign -a message that Plato himself saw Theaetetus as a kind of prologue or introduction to Sophist. 45 Plato: Theaetetus 146e.
wisdom-sophia was ideas. Within Plato's metaphorical framework, only God could possess such knowledge, while the philosopher remained on a permanent journey in its direction. The ontic status of ideas made knowledge similar to Parmenides's notion of being, while in Theaetetus, Socrates clearly emphasizes that one should not accept or assume "Let us stick close to the statement we made a moment ago, and assume that nothing exists by itself as invariably one." 46 The first part of Parmenides ends with the conclusion that the theory of ideas should be thoroughly verified by eliminating the aporias inherent in the entire system. 47 A careful reading of Theaetetus allows us to find many places in the dialogue pointing to the theory of the five highest types already developed in Sophist, especially regarding identity and difference, to which Plato's Socrates confers ontic status, 48 as well as an important mention, contradicting the findings of the theory of ideas, which may refer to the propedeutic of the science of principles -a mention of "two prototypes that stand in the womb of true being." 49 Another premise is the form of discussion, or rather Socrates's line of argument. Generally speaking, it boils down to formulating a number of hypotheses, which are subsequently challenged in the course of the dialectical procedure. One can venture to say that this is an exemplification of the thesis formulated in Parmenides, or rather a postulate concerning the correct implementation of the procedure of the form of dialectic I call hypothetical dialectic. Its first description can be found in Phaedo, often called after G. Reale the "second voyage." 50 The older Plato, hiding in Parmenides behind the mask of the philosopher from Elea, accuses the younger Plato -Socrates -of being careless in following the procedures of hypothetical dialectic. He did not complete the procedurally necessary step of verifying the formulated hypotheseis, which consists in setting a particular hypothesis against the opposite hypothesis. The strict judge of Plato's theory of ideas demands from Plato verification of the form of hypothetical dialectic he presented in Phaedo, when Socrates, formulating a strong assertion of the highest degree of generality, somehow stopped there, failing to consider the consequences that the opposite hypothesis would bring about. Parmenides, whose mask an older and wiser Plato dons in the dialogue, and who has since been trained in dialectical sophisms by Megarian dialecticians, demands that the younger Plato allocate each hypothesis, regardless of its generality and power, the opposite hypothesis and examine each of their consequences, comparing and juxtaposing the conclusions.
In Theaetetus, Plato no longer makes the "mistakes of youth." Each hypothesis has a contradictory hypothesis assigned to it in the structure of dialogue. Plato's Socrates juxtaposes and verifies them and, often as a result of this verification, rejects them. This form of dialogue may suggest its aporeticity. However, if we treat this apparent aporeticity as a record of hypothetical dialectical procedures, we must acknowledge that the project itself is constructive and has tremendous didactic and cognitive value.
Let us take a look at the hypothesis formulated in Theaetetus and try to find constructive content in them, keeping in mind that Plato, in his attempts to define what knowledge is, must argue with many opponents: not only with Protagoras and his concept of the equality of judgments, but also with the atomists, Antisthenes, and with himself -a younger Plato, who considered ideas to be the first being and the object of knowledge.
The argument that Plato puts in Socrates's mouth is impressive in terms of its logical order and consistency. If we take as a starting point, as Socrates does with Theaetetus, that the concept of knowledge-episteme is not an empty concept, 51 as well as the fact that knowledge cannot be equated with skills (technai), or with facts memorized on a given topic, 52 we must recognize that it always belongs to each individual who is "pregnant in thought," acquired by him/her in a specific activity of the senses and reason, which Socrates in the dialogue calls the soul.
To undertake an attempt at defining what knowledge is, one must begin from scratch -from what appears first in the process of cognition. 53 Therefore, we must consider the thesis that knowledge is perception (aisthesis). 54 This idea was rejected by Plato during the time of the Middle Academy; in his view, the object of perception was not being, but things -ta chremata, changeable and transient, about which one could 51 And this had already been established at the end of the first part of Parmenides. 52 Plato: Theaetetus,147c. 53 It is worth emphasizing that the author of the apocryphal VII Letter shows a different hierarchy of data (the five disclosures of the subject) necessary in dialectical procedures -it starts with the name, through the definition, the object-the thing itself, to knowledge. 54 Ibid.,151e. only hold opinions -doksai. In Theaetetus, however, Plato states that perception somehow concerns being, 55 so it becomes necessary to consider the object of perception -what it is exactly that appears to us in perception. In a multi-faceted polemic -explicit with Protagoras, implicit with Antisthenes -it is established that knowledge cannot be perception, 56 as perception is singular, individual, subjective, of a temporal nature, and depends on the perceiving sense organ. 57 In addition, the image of the perceived thing -phantasia -is located in the soul. It is in the soul that the results of a sensory view are segregated and organized based on criteria that are not given to us in this view, such as similarity and dissimilarity, identity and difference. 58 A sensory view can therefore only provide data for reasoning procedures. Only the soul-reason, which performs operations on the results of sensory viewing, can be the seat of knowledge. 59 Perception cannot grasp the truth (aletheia) or the essence (ousia) of a thing 60 -something that is common to all, that is their principle and beginning, but is not subject to a sensory view.
In his next hypothesis, Socrates puts forward the thesis that knowledge should be sought in the activity of the soul that, on the basis of perceptions, after organizing and segregating them (dianoeisthai), undertakes an attempt, which Plato calls doxadzein, 61 and which results in doxa. This term causes much difficulty for those attempting to interpret Plato's Theaetetus. Plato's Polish translator erroneously translates it as "judgment," 62 which has led to misunderstandings and ambiguities. In my view, this term should be translated as "opinion," in accordance with the philosophical tradition (and not limited only to pre-Platonic tradition). Since the time of Xenophanes of Colophon, the term opinion (doxa) functioned as the opposite of knowledge, cf. Diels FVS Xenophanes B 35; for Parmenides, "the opinions of mortals," resulting from fallible sensory perception, were opposed to truth in its ontic aspect, in the realm of predicating of being. Plato used the term doxa to refer to the results of the sensory view to which the world of things is subject. The predicates of truth (doxa alethes) and falsehood (doxa pseudes) may be attributed to opinion, but in what sense?
Thus, knowledge is an opinion. 63 Is every opinion knowledge, however? Knowledge understood this way must meet an essential condition: it must be a "true" opinion. And here for the first time Plato, through the words of Socrates, admits that there may also be mistaken, or rather false (pseudes), opinions. For the first time, the term pseudos, pseudes is used in an epistemological context and signifies the opposite of truth. False opinions are possible, and Socrates's reasoning reveals the path that the philosopher had to follow in order to recognize the possibility of "thinking things that are not," in the sense of thinking that cannot be reconciled with the truth of being. We must remember, however, that Plato emphasizes that the intellectual action he calls dianoeisthai, as a result of which the soul begins to have opinions (doxazesthai), and its product -doxa -are realized in the soul 64 ; it is "the soul's conversation with itself," which is not objectified in speech. Errors, such as assigning existence to what does not exist or a confusion of predicates, can only appear in this sphere of intellectual activity, unless it is subjected to certain rigors. If an opinion is to count as knowledge, it must be a true opinion. 65 But how can one distinguish between true and false opinions? This question is of particular importance in Plato's time, and not only in the realm of philosophy and epistemology; Socrates recalls examples from every day life -we need look no further than in the courts, where it is easy, as Gorgias emphasizes in Defense of Palamedes, to create false opinions in people using the arts of persuasion and rhetoric. What determines whether thinking -that intellectual activity of the soul -will result in a form of opinion to which the predicate of truth may be attributed?
Plato views the logos as an instrument for verifying opinions. Another attempt -hypothesis -defines knowledge as "an opinion to which the predicate of truth is attributed by virtue of the logos." 66 Throughout Socrates's arguments several meanings of the term appear. However, the reader does not have to make a choice between them, because they all complement each other harmoniously. In terms of the order of appearances, which is not necessarily identical with the hierarchy of meanings, the meaning comes to the fore, which I will call the objectification of opinion in the form of a statement. An opinion is born and remains in the soul. Spoken-objectified, it becomes subject to certain rules of expression. A statement, as noted at the beginning, must predicate something of something. It is therefore a "composition of names" -symploke onomaton, because only a composition of names can be verified and predicate truthfully. 67 A name itself does not predicate anything, and neither truth nor falsehood can be attributed to it. 68 It is their composition in the form of a sentence that constitutes a predication. Therefore, knowledge is possessed by one who can objectify it in the form of a statement that can be confirmed or denied. This is the first pre-definition of a judgment in the history of philosophy, which Plato in Sophist will later refer to as the logos.
Further attempts at determining the content of the term logos can be reduced to establishing what should be included in a statement-objectification of a true opinion. And so, in an unwritten reference to Antisthenes's ideas already criticized by Plato in Euthydemus, Socrates will examine predicating something by enumerating its "components" (only to negate such predication), as well as whether predicating or defining per genus proximum et differentiam specificam 69 can be considered knowledge. It 66 This is how I translate the Platonic phrase: doksaalethes meta logou (cf. 201c: Theat. "But, my friend, if true opinion and knowledge were the same thing in law courts, the best of judges could never have true opinion without knowledge; in fact, however, it appears that the two are different"; Trans. Harold N. Fowler). 67 Ibid., 202b-c: "they can only be named, for they have only a name; but the things composed of these are themselves complex, and so their names are complex and form a rational explanation; for the combining of names is the essence of reasoning. Thus the elements are not objects of reason or of knowledge, but only of perception, whereas the combinations of them are objects of knowledge and expression and true opinion. When therefore a man acquires without reasoning the true opinion about anything, is mind has the truth about it, but has no knowledge; for he who cannot give and receive a rational explanation of a thing is without knowledge of it; but when he has acquired also a rational explanation he may possibly have become all that I have said and may now be perfect in knowledge. Is that the version of the dream you have heard, or is it different?" (Trans. Harold N. Fowler). 68  comes as no surprise that Socrates is unable to take a definite position in this matter. As mentioned above, there are many reasons to consider the dialogue Theaetetus as a late work of Plato's. During the Middle Academy, the objects of knowledge identical with wisdom were ideas, as the modelefficient causes of things, ideas as general concepts with an ontic status, ideas-first beings. The younger Plato would accept a view of knowledge, whose object would be what is common to sets of things distinguished on the basis of "one idea." 70 The older Plato states that such knowledge can encompass only that set distinguished due to a common feature, but will not take into account the individual characteristics of individual objects.
Perhaps it is here that we find an indication of the problem of the principle of individuation, left unresolved by Plato and,I think,by Aristotle. 71 But Socrates also rejects the view of knowledge, whose object would be individual differences in sets of objects. Does Plato's Socrates, as a master of techne maieutike, really fail in the dialogue? Is the final observation that knowledge is not true opinion thanks to the logos, that the epistemon differs from one who holds true beliefsdoxasthes -to destroy the investigation of the whole dialogue?
Due to the time when the dialogue was written, I assume that Plato in Theaetetus could not have yet formulated a theory of knowledge objectified in a judgment, because he had not determined what the first form of being is: he undermined the legitimacy of the theory of ideas, while in his research had not yet reached the notion of principles/archai. Moreover, in writing he consciously posed the question: "What is knowledge?," knowing that he could not answer it. As mentioned above, this dialogue should be placed at the stage of the development of Platonic thought when Plato himself challenged the form of his theory of ideas, and had not yet worked out the theory of principles as the form of the first being. The object of knowledge can only be something to which the predicate of being belongs, which one can predicate of in the form of logos -a true statement, the truth of which will be confirmed by dialectical procedures -logoi kai logismoi -synoptic, hypothetical, and diairetic dialectic. Plato, having rejected ideas as the first being in ordine essendi, continually seeks the first principles -archai, realizing, however, that they can be reached in the process of cognition only by way of the logos. Theaetetus is essentially devoted to searching for the theory of logos as an instrument of cognition, 70 Ibid., 208e: "Then he who possesses right opinion about anything and adds thereto a comprehension of the difference which distinguishes it from other things will have acquired knowledge of that thing of which he previously had only opinion" (trans. Harold N. Fowler). 71 Ibid.
as a research procedure, and as a form of the objectification of research results -a judgment. Thus, in the development of Greek thought, there came a moment when the notion of judgment-logos as a verifiable statement, subordinated to the rules of thinking, that has as its object the knowledge of being, could be formed. As mentioned, such a notion was adopted by Plato in the dialogue Sophist, in which he formulated the definition of a false judgment. In this way Plato made a major breakthrough in Greek epistemology, showing that it is possible to falsely predicate being.