NeoplatonismNeoplatonism is a version of Platonic philosophy that emerged in the 3rd century AD against the background of Hellenistic philosophy and religion. The term does not encapsulate a set of ideas as much as a series of thinkers. Among the common ideas it maintains is monism, the doctrine that all of reality can be derived from a single principle, "the One". Neoplatonism began with Ammonius Saccas and his student Plotinus (c. 204/5–271 AD) and stretched to the 6th century AD.
Platonic epistemologyIn philosophy, Plato's epistemology is a theory of knowledge developed by the Greek philosopher Plato and his followers. Platonic epistemology holds that knowledge of Platonic Ideas is innate, so that learning is the development of ideas buried deep in the soul, often under the midwife-like guidance of an interrogator. In several dialogues by Plato, the character Socrates presents the view that each soul existed before birth with the Form of the Good and a perfect knowledge of Ideas.
Analogy of the sunThe analogy of the sun (or simile of the sun or metaphor of the sun) is found in the sixth book of The Republic (507b–509c), written by the Greek philosopher Plato as a dialogue between his brother Glaucon and Socrates, and narrated by the latter. Upon being urged by Glaucon to define goodness, a cautious Socrates professes himself incapable of doing so. Instead he draws an analogy and offers to talk about "the child of goodness" ("ἔκγονός τε τοῦ ἀγαθοῦ").
Western philosophyWestern philosophy encompasses the philosophical thought and work of the Western world. Historically, the term refers to the philosophical thinking of Western culture, beginning with the ancient Greek philosophy of the pre-Socratics. The word philosophy itself originated from the Ancient Greek (φιλοσοφία), literally, "the love of wisdom" φιλεῖν , "to love" and σοφία sophía, "wisdom").
PlatonismPlatonism is the philosophy of Plato and philosophical systems closely derived from it, though contemporary Platonists do not necessarily accept all doctrines of Plato. Platonism had a profound effect on Western thought. In its most basic fundamentals, Platonism affirms the existence of abstract objects, which are asserted to exist in a third realm distinct from both the sensible external world and from the internal world of consciousness, and is the opposite of nominalism.
Theory of formsThe theory of Forms, theory of Ideas, Platonic idealism, or Platonic realism is a metaphysical theory, attributed to the Classical Greek philosopher Plato, suggesting that the physical world is not as real or true as timeless, absolute, unchangeable ideas. Ideas according to this theory, conventionally capitalized and translated as "Ideas" or "Forms", are the non-physical essences of all things, of which objects and matter in the physical world are merely imitations.
Analogy of the divided lineThe analogy of the divided line (grammē dicha tetmēmenē) is presented by the Greek philosopher Plato in the Republic (509d–511e). It is written as a dialogue between Glaucon and Socrates, in which the latter further elaborates upon the immediately preceding analogy of the sun at the former's request. Socrates asks Glaucon to not only envision this unequally bisected line but to imagine further bisecting each of the two segments. Socrates explains that the four resulting segments represent four separate 'affections' (παθήματα) of the psyche.
Nicomachean EthicsThe Nicomachean Ethics (ˌnaɪkɒməˈkiən; ˌnɪkəməˈkiən; Ἠθικὰ Νικομάχεια, Ēthika Nikomacheia) is Aristotle's best-known work on ethics: the science of the good for human life, that which is the goal or end at which all our actions aim. It consists of ten subsections, referred to as books or scrolls, and is closely related to Aristotle's Eudemian Ethics. The work plays a pre-eminent role in explaining Aristotelian ethics. The theme of the work is a Socratic question previously explored in the works of Plato, Aristotle's friend and teacher, about how men should best live.
Allegory of the caveThe Allegory of the Cave, or Plato's Cave, is an allegory presented by the Greek philosopher Plato in his work Republic (514a–520a) to compare "the effect of education (παιδεία) and the lack of it on our nature". It is written as a dialogue between Plato's brother Glaucon and his mentor Socrates, narrated by the latter. The allegory is presented after the analogy of the sun (508b–509c) and the analogy of the divided line (509d–511e). In the allegory "The Cave", Plato describes a group of people who have lived chained to the wall of a cave all their lives, facing a blank wall.
Theaetetus (dialogue)The Theaetetus (ˌθiːɪˈtiːtəs; Θεαίτητος) is a philosophical work written by Plato in the early-middle 4th century BCE that investigates the nature of knowledge, and is considered one of the founding works of epistemology. Like many of Plato's works, the Theaetetus is written in the form of a dialogue, in this case between Socrates and the young mathematician Theaetetus. In the dialogue, Socrates and Theaetetus attempt to come up with a definition of episteme, or knowledge, and discuss three definitions of knowledge: knowledge as nothing but perception, knowledge as true judgment, and, finally, knowledge as a true judgment with an account.