The Philebus (, ) is a work by the ancient Greek philosopher Plato. Written in dialogue form, it presents a fictional conversation between Plato's teacher Socrates and two young Athenians, Philebus and Protarchus. The main topic is the ethical evaluation of pleasure.

Philebus and Protarchus are hedonists who consider pleasure as the highest good and equate it with the absolute Good. Socrates represents the opposing view, prioritizing reason and insight. While he does not dispute the legitimacy and value of pleasure, he points out the diversity of pleasures and argues for a more nuanced assessment. He rejects some forms of pleasure as harmful and assigns a subordinate rank in the hierarchical value order to the remaining "pure" pleasures. The distinction between types of pleasure leads to general considerations about the unity and plurality of types that are subsumed under a generic term, and about the categories into which all being can be divided. Socrates explores the causes, origins, and characteristics of various forms and mixtures of pleasure and pain that occur in human life and their changing combinations, which result in diverse emotional states. The specifics of each form of pleasure are analyzed, and the reasons for their varying evaluations are explained. At the end of the dialogue, Socrates presents a universal value order. In this, proper measure, proportionality, takes the highest place, and pleasure – as far as it is justified – takes the lowest. Harmful pleasures are to be avoided. The right mixture of desired factors is supposed to enable a successful life and bring about a balanced emotional state. Protarchus agrees, while Philebus no longer comments.

The Philebus is considered one of Plato's most challenging dialogues. Manuscripts of the work give it the subtitle "peri hēdonēs, ēthikos" ("ethics/moral concerning pleasure") implying that its topic is "concerning pleasure" and it is a work on ethics — that is, the question of what way of life is best. However, in addition to the core theme of pleasure, it discusses a range of other philosophical questions; "there are large parts in the dialogue that deal with dialectics and ontology but have nothing to do with pleasure and ethics, or if so, only indirectly". In modern research, the classification of all being into four classes by Socrates and the relationship of this classification to Plato's Theory of Forms and to his "unwritten doctrines" receive particular focus.

Composition Research is almost unanimous in classifying Philebus among Plato's "late" dialogues. It has been proposed that the work was composed between 360 and 347 BC, and that it is among the last of the late dialogues of Plato. This is supported both by statistical linguistic evidence and the content's similarity to other late works, especially the Timaeus. However, the prominent role of the character Socrates in this late work is atypical; many of the other "late" dialogues do not figure Socrates as the main speaking character. Some prefer a slightly earlier dating – originating in the last phase of Plato's middle period. For a more precise placement within the group of late dialogues, there is a lack of sufficient evidence. The hypothesis that Philebus was Plato's response to the hedonism of Eudoxus of Cnidus has led to the suggestion that the composition dates soon after 360 BC, though this attribution is highly uncertain.

The textual transmission of Philebus is more problematic than that of other dialogues due to some corruptions, posing special challenges for textual criticism. The oldest surviving medieval manuscript of Philebus was produced in the year 895 in the Byzantine Empire for Arethas of Caesarea,Oxford, Bodleian Library, Clarke 39 (= „Codex B“ of the Plato textual transmission). while older manuscripts are limited to a few small papyrus fragments.Corpus dei Papiri Filosofici Greci e Latini (CPF), Part 1, Vol. 1***, Firenze 1999, p. 285–289, 508–512.

Place, time, and participants Unlike many other Platonic dialogues such as the Phaedo or the Theaetetus, Philebus is not structured as a reported narrative from someone who had heard the conversation, rather, the dialogue begins abruptly, without any framing action. Nothing is revealed about the place, time, and occasion of the conversation. Athens, the hometown of Socrates, is the only possible setting. In addition to the three interlocutors Socrates, Protarchus, and Philebus, a group of young men is also present, who only listen silently. They are apparently admirers of Philebus, whose homoerotic beauty is valued. Although the dialogue is named after him, Philebus plays only a minor role. The debate takes place between Socrates and Protarchus.

Socrates

Socrates, as in most Platonic dialogues, is the main character, the knowledgeable philosopher who leads and dominates the debate and helps the others gain insights. Unlike in the early dialogues, where he holds back his own opinion and leads his interlocutors to new thoughts with purposeful questions, here he develops his own theory. Since the dialogue is a fictional literary construct, the concept that Plato puts in Socrates' mouth should not necessarily be regarded as the position of the historical Socrates, although some scholars have noted that the ethical attitude of the dialogue character roughly corresponds to that of his real-life model.

Philebus Philebus is young, more a teenager than a young man. His beauty is repeatedly emphasized. His special relationship with the goddess of love Aphrodite, to whom he gives the name of pleasure (Hedone), apparently reflects his view that his commitment to hedonism is in line with the goddess.

It is notable that Philebus, while being the title character and putting forward the initial thesis, leaves the defense of the thesis to Protarchus, while he himself rests and listens. He rarely speaks, and at the end, he silently accepts the refutation of his thesis. He is lazy, interested only in enjoyment, and shies away from the mental effort of a debate. His worldview is simple. His appearance and entire demeanor match the negative image of an incompetent, self-satisfied, and unteachable hedonist that the author wants to present to the reader. Friedländer suggests that Philebus does not participate in the philosophical investigation because he embodies an irrational principle that does not give an account of itself.

There is no evidence outside the dialogue for the existence of a historical acquaintance of Socrates named Philebus. It is quite possible that he is a purely fictional character. This is suggested by the fact that no historical bearer of this name is known, and it is a nickname that fits the character ("youth lover" or "friend of youthful pleasure"). Further indicators of fictionality are that the name of his father is not mentioned, and Plato has not given him a profile that would allow for historical classification.

It is possible that Plato attributed features of the mathematician and philosopher Eudoxus of Cnidus to Philebus. Eudoxus, a younger contemporary of Plato, was a hedonist, and the critique of hedonism in Philebus was, according to a research hypothesis, directed against his doctrine.

Protarchus As a dialogue character, Protarchus, like Philebus, represents the Athenian upper class, in which educational efforts were valued and philosophical topics sparked interest during the time of Socrates. In contrast to Philebus, Protarchus proves to be willing to learn and flexible. He is modest and open to subjecting his hedonistic worldview to an unbiased examination, whereas Philebus declares from the beginning that he will not change his opinion. Eventually, Protarchus is convinced by Socrates, after having tried to defend his position for some time.

Protarchus is considered by some scholars as more likely to be a historical person than Philebus, though doubts still exist. In the dialogue, Socrates calls him "son of Callias". Dorothea Frede believes that Protarchus was one of the two sons of the wealthy Athenian known in the scholarly literature as "Callias III" who are mentioned in Plato's Apology. They were, according to Plato's statements there, taught by the Sophist Euenus of Paros. In Philebus, Protarchus speaks respectfully of the famous rhetoric teacher Gorgias and identifies himself as his eager student. It is also possible that Plato's Protarchus is identifiable with an author – apparently a Rhetorician – of the same name cited by Aristotle.

Content Philebus is considered challenging and difficult to understand. As early as 1809, the influential Plato translator Friedrich Schleiermacher noted in the introduction to the first edition of his translation: “This dialogue has always been considered one of the most important, but also one of the hardest among the works of Plato.” However, recent research has emphasized the well thought-out structure of the Philebus, including the doctrine of affect and the approach to a theory of comedy.

Reference numbers are given in Stephanus pagination; the dialogue runs from page 11a-67b.

Developing the preconditions (11a-31b) Initial situation (11a-12b) The dialogue starts abruptly in the middle of ongoing conversation. Philebus has posited that pleasure or delight (hēdonḗ) is equivalent to "the good" and desirable for all living beings. Pleasure leads to the state of Eudaimonia ("happiness") and thus brings about a successful life. Socrates has disputed this and argued for the counter-thesis that there are more important and advantageous things: reason, knowledge, and memory, a correct understanding, and truthful deliberation. This debate has made Philebus weary, so he now leaves it to Protarchus to defend their common standpoint against Socrates' critique. Protarchus, however wishes to discuss the matter with an open mind, whereas Philebus outright states that he will always hold on to the precedence of pleasure.

Pleasure and pleasures (12c-14b) Socrates begins his critique of the glorification of pleasure by noting that pleasure is not a simple, uniform entity. Rather, there are diverse and even disparate phenomena that are grouped under this term. The pleasure of a profligate person is not comparable to that of a prudent one, and the pleasure of a reasonable person is not comparable to that of a fool. Protarchus counters that although the causes of pleasant feelings are opposites, the effect is always the same. He argues that pleasure is always pleasure and always good. To counter this, Socrates makes a comparison with the concept of "color": both black and white are colors, yet one is the exact opposite of the other. Similarly, there are opposing pleasures; some are bad, others good. Protarchus initially does not concede this; only when Socrates also describes his favored good, knowledge, as diverse, does Protarchus admit to the variety of pleasures, as his position is not disadvantaged by this view.

One and many (14b-17a) The general problem that the conversationalists have encountered is the relationship between one and many, one of the core themes of Platonic philosophy, which questions how it is possible that pleasures or reason can both consist of different kinds but yet still form a unity that justifies the common concept. This is not about the specific instances of each concept, but about the general class of experiences that underlies them, i.e., concepts like "human," "the beautiful," or "the good" and their subdivisions.