Plato's Philosophy: Key Concepts and Terms Defined

Platonic Vocabulary: Essential Concepts

Soul

The soul, *imprisoned* in a material body. Plato identifies three parts of the soul:

• Rational (Logistikon): Associated with *prudence* or wisdom.
• Spirited (Thymoeides): Associated with *fortitude* or courage.
• Appetitive (Epithymetikon): Associated with *temperance* or moderation.

Science (Episteme)

Knowledge of the most universal and immutable truths. Plato distinguishes two types of cognition: *Science* and *Opinion*.

Knowledge

The kind of intellectual vision that perceives the *Idea* or *Form*.

Belief (Pistis)

A degree of *opinion* based on the direct perception of sensible things.

Dialectic

A rigorous science and method of philosophical inquiry. It involves counterposing arguments to overcome contradictions and ascend to higher reason, ultimately grasping the *Forms*.

Education (Paideia)

The process of formation and instruction for citizens, ideally led by the state.

Essence (Ousia)

In Platonic thought, *Essences* are the *Ideas* or *Forms* that serve as models for things. They are separate from the sensible world yet make the intelligible world known.

State (Polis)

Refers to a political regime or city-state. *Polis* signifies 'city' in its legal and political sense.

Happiness (Eudaimonia)

A state of flourishing or grace achieved when one connects with the *Good*.

Philosopher

One who can grasp that which is always unchanging and truly *is* (the *Forms*).

Form (Eidos/Idea)

What is visible to the eyes of reason, to intelligence; what truly *is* versus what merely *seems*.

Rulers (Philosopher-Kings)

Those who lead the city, managing the state and educating citizens to achieve sound *opinion*. Their purpose is to establish just laws for the city, even within the 'cave' (the sensible world).

Guardians (Auxiliaries)

The military class of the state and city. Their mission is to preserve order and defend the city.

Idea of the Good

The ultimate goal of *Dialectic*, the highest purpose of intelligence. It is the culmination of the community of *Ideas*, the supreme principle of the intelligible realm.

Imagination (Eikasia)

A sensitive form of cognition based on the perception of images, categorized within *opinion*.

Intelligence (Noesis)

Contemplation achieved through wisdom, the highest cognitive level, directly perceiving authentic reality (the *Forms*).

Justice (Dikaiosyne)

Whose function in this world is to realize the *Good Idea*. It is the basis for the constitution and preservation of the city.

Intelligible World (Kosmos Noetos)

In short, a reality of *Essences* presided over by the *Good*, the true homeland of the soul, the realm outside the 'cave,' the object of *reminiscence* that nourishes true knowledge.

Sensible World (Kosmos Aisthetos)

The sensible realm, halfway between being and non-being. The reality of this nature is participatory and mimetic in relation to the intelligible *models*.

Opinion (Doxa)

Something halfway between *knowledge* and ignorance. Its object is the sensible world. Within *opinion*, Plato distinguishes two kinds: *conjecture* and *belief*.

Thought (Dianoia)

The reasoning process that, using geometric figures as *hypotheses*, progresses towards more general conclusions. It serves as a *propaedeutic* to finally grasp the *Idea of the Good*.

Reminiscence (Anamnesis)

A memory that remains in the soul from the *intelligible world*. Knowledge is described as a longing for this forgotten truth.

Virtue (Arete)

Excellence and the fulfillment of a being's proper function, according to its definition. *Virtue* is always associated with the *Idea of the Good* or *Beautiful*.