One of the ways in which Plato has captured the popular imagination is with the claim that the philosopher can feel ers, passionate love, for the objects of knowledge. Why should Plato make this claim? In this chapter, I explore Plato’s treatment of philosophical ers along three dimensions. First, I consider the source of philosophical ers. I argue that it is grounded in our mortality and imperfection, which give rise to a desire for immortality and the immortal. Second, I turn to the object of philosophical ers. I suggest that it is an arresting response to beauty, through which we come to value the ideal properties of the forms. Finally, I address the nature of ers. I claim that it is a focusing desire, that overrides other concerns and causes us to overwhelmingly focus on its object. I conclude the chapter by considering the problem Vlastos famously raises for Plato’s account of ers: can it do justice to disinterested, interpersonal love? In agreement with Vlastos, I claim that one who comes to grasp the forms will cease to feel interpersonal love; however, I also suggest that ers can give rise to philia, beneficent concern with the wellbeing of others.

In the Hippias Minor, Socrates argues that the expert in a given domain is the one in a position to voluntarily violate the rules of that domain. For example, the expert archer can ensure that her arrows miss the target, whereas the novice archer might accidentally hit the target she’s trying to miss. Socrates claims, shockingly, that this point holds for justice as well: it is the expert in justice who will have the power to deliberately act unjustly. Though some accuse Socrates of drawing this conclusion on the basis of uncritical reliance on the craft analogy, I argue that in fact Socrates is identifying common ground between a variety of forms of practical normativity. In any activity that can be assessable as going well or badly, those who intentionally flout the norm, by erring on purpose, are better at it than those who unintentially flub the norm, by erring accidentally. Socrates’ argument places powerrather than the exercise of powerat the heart of ethics. The Hippias Minor shows why Socratic ethics is an ethics of virtue, rather than an ethics of virtue activation.

Plato’s philosophical thinking begins from views and assumptions that he presupposes in his readers or in himself, whether or not he states them explicitly. This chapter surveys the following influences: (1) Homer. (2) Political developments and the moral questions they raise. (3) The interactions of natural philosophy (‘Presocratic’ philosophy) and religion. (4) The epistemological questions arising from natural philosophy. (5) Sceptical tendencies in naturalist epistemology. (6) Sophistic and rhetoric and the intellectual and political tensions connected with them. (7) Plato’s reactions to natural philosophy, sophistic and rhetoric. (8) Socratic inquiry and its sources in drama and forensic oratory.

This chapter highlights the close interconnection between cosmology and human nature in the Timaeus. According to Timaeus, human beings are not merely part of the cosmos; they play a crucial role in explaining how the cosmos came to be. The cosmos must contain three kinds of mortal beings in order to be complete, and all three derive from human beings, as a result of varying degrees of moral and cognitive failure. Recognizing the distinctive role human beings play in completing the cosmos complicates the standard picture of Timaeus’ cosmology, as well as his account of human nature. While in large part the cosmos is a product of divine craft, in some part it is the product of the inevitable disturbance of immortal souls due to mortal embodiment. Human beings have a special status as the first generation of mortal beings, as well as the only ones produced solely by divine craft. However, this distinction does not extend beyond the first generation, nor does it include any women. Ultimately, Timaeus’ account of human nature blurs the lines between humans and gods, as well as between humans and non-human animals.

We have little information from external sources about the order in which Plato composed his dialogues. In the mid-nineteenth century, scholars began to study stylistic affinities among certain groups of dialogues, conjecturing that stylistically similar works were composed during the same period of Plato’s life. A consensus among scholars working independently of each other emerged, according to which the Sophist, Politicus, Philebus, Timaeus, Critias, and Laws were placed in a discrete chronological group – thought to be late, in part because we have external evidence that Laws is a late work. In recent decades, computer analysis has aided the investigation of Plato’s word choice and style. These studies can also address long-standing doubts about the authenticity of some works attributed to Plato, including his Letters. Using a variety of techniques, the Republic, Parmenides, Phaedrus, and Theaetetus can also be put into a chronological group that comes before the late dialogues but after the other dialogues. Some scholars have sought to use stylometric measures to sort the earlier dialogues, but there is not much basis for any such arrangement.

There is one fundamental argument in the Republic for the conclusion that justice is the greatest good. It begins in Book II; although adumbrated in Book IV, it is not completed until Book IX; and it draws essentially on material in Books VI and VII about Platonic forms, knowledge, and philosophical training. Justice consists in the rule of reason over spirit and appetite, but to understand the value of this state fully we must see how it is instantiated in the philosopher. Goodness consists in order, and by cognizing and loving forms (the most orderly objects there are) the philosopher possesses the highest goods. A fully just person is a creator and lover of orderly relationships among human beings. This condition exists to some degree in all just individuals, but it is most fully present in those who understand what justice is – philosophers.

This chapter offers a guide to reading Plato’s dialogues, including an overview of his corpus. We recommend first considering each dialogue as its own unified work, before considering how it relates to the others. In general, the dialogues explore ideas and arguments, rather than presenting parts of a comprehensive philosophical system that settles on final answers. The arc of a dialogue frequently depends on who the individual interlocutors are. We argue that the traditional division of the corpus (into Socratic, middle, late stages) is useful, regardless of whether it is a chronological division. Our overview of the corpus gives special attention to the Republic, since it interweaves so many of his key ideas, even if nearly all of them receive longer treatments in other dialogues. Although Plato recognized the limits inherent in written (as opposed to spoken) philosophy, he devoted his life to producing these works, which are clearly meant to help us seek the deepest truths. Little can be learned from reports of Plato’s oral teaching or the letters attributed to him. Understanding the dialogues on their own terms is what offers the greatest reward.

The chapter offers a reading of Socrates’ fourfold classification, at Philebus 23c-27c of “all the things now in the universe” into what is without limit (the apeiron), limit (peras), mixtures of these two (the meikton) and the cause of said mixtures (aitia). Contrary to the classification’s more typical treatment as a general window onto Plato’s late ontology and whatever may be its broader horizons, this classification is argued to be tailored to the project of the dialogue, directed to an analysis of the metaphysics of craft objects. In developing and explaining the classification, Socrates puts in place material for an analogy drawn from the craft of medicine to the effect that as medicine stands to health so stands some as yet unidentified craft to the good condition of soul that is the dialogue’s central focus, responsible for the happy human life. In thus articulating a framework for the historically influential idea of a craft of human living, Socrates provides a heuristic through which, in the remainder of the dialogue, the life’s character and elements may be systematically explored with a view to the dialogue’s overall contest between pleasure and intelligence.

The chapter aims to show that Plato’s engagement with mystery cults – the Eleusinian mysteries and Orphic cults in particular – can illuminate centrally important topics of Plato’s philosophy, including his conception of the philosophical life, its relation to the human good, the role of memory in the knowledge of the Forms, and the soul’s kinship to the divine. It explores why and how Plato presents philosophy as the true initiation which can fulfil the promise of the mystery cults to offer the best human life and afterlife. It analyses why and how Plato describes the knowledge of the Forms on the model of the direct encounter with the divine at the culmination of a mystery ritual. It further suggests that the ‘birth’ announced at the highest point of the Eleusinian mysteries can shed new light on the role of ‘giving birth’ at the culmination of the philosophical life in the Symposium. Finally, it shows how Pythagorean and Orphic focus on memory offered Plato a framework to develop his account of the relationship between the soul and the divine Forms, reincarnation, and the fate of our soul in the afterlife.

In the Meno, Socrates considers, and replies to, Meno’s paradox. According to the paradox, whether or not one knows something, one can’t inquire into it. The paradox has been understood in a variety of ways: some think it is invalid; others think it is valid but unsound; those who favor the second option disagree about what the false premise is. I argue that, as Socrates understands the paradox (but not, perhaps, as Meno does), it is valid but unsound: not knowing doesn’t preclude inquiry, since one can inquire on the basis of true beliefs that fall short of knowledge. Socrates develops this theme in the geometrical discussion with one of Meno’s slaves. Another part of his reply is the theory of recollection, which is often thought to posit innate knowledge. I argue, however, that, though the theory of recollection posits prenatal knowledge, it doesn’t posit innate knowledge. I also set the paradox in a broader context, exploring the Meno’s views on inquiry, definition, knowledge, and belief.

This chapter investigates Plato’s thoughts on poetic creativity by tracing a path from a traditional divine inspiration view to a new kind of inspiration, which transforms the poet into a philosopher. The path begins with divine inspiration in the Ion, then turns to the power of public poetry in the Gorgias. Next is the beginning of a new conception of poetic creativity in the Symposium. By considering poetry as a kind of communication between a lover and the beloved, Plato views poetry as a basis for a philosophical ascent to the Form of Beauty. In the Republic, Plato emphasizes further the power of poetry by classifying traditional poetry as a degraded kind of imitation. He highlights its power to corrupt the listener by strengthening irrational emotions. In the Phaedrus, Plato extends his notion of poetic creativity to linguistic communication in general, thereby developing further his notion of philosophical communication as a creative force generated by love. In the end, Plato pulls together both his denunciation of traditional poetry and his new conception of poetic creativity by offering a new type of public poetry in the Laws, consisting ultimately of his own body of laws.

This chapter addresses Plato’s conception of philosophy by examining how the Apology of Socrates represents Socrates as a model lover of wisdom. This Socrates loves expertise about how to live well, and he does so in three ways: (i) by examining others to test them for this expertise and to confirm that only the gods possess it, (ii) by pursuing the expertise, nonetheless, to improve his beliefs about how to live well, and (iii) by exhorting others to examine themselves and to pursue wisdom. The chapter pays special attention to Socrates’ conceptions of knowledge, living well, and teaching, and it suggests briefly how Plato tweaks or transforms this Socratic model in other dialogues.