Plato's Theory of Knowledge and its Ontological Foundations

The Sensible and Intelligible Worlds

Plato's theory of knowledge is intrinsically linked to his ontological dualism, which distinguishes between the sensible world and the intelligible world. In the ever-changing sensible world, we can only attain doxa (opinion), a sensory-based knowledge that, at best, coincides with reality. This inadequate knowledge, based on perception, satisfies only the ignorant.

The intelligible world, characterized by eternity, immutability, and permanence, offers episteme (true knowledge), providing wisdom and understanding of causes. This is the knowledge sought by the sage, who can demonstrate truth to others.

Levels of Knowledge: The Divided Line

In the Republic's allegory of the divided line, Plato further elaborates on these levels of knowledge. Doxa is divided into:

• Eikasia: The lowest level, corresponding to shadows and illusions in the allegory of the cave.
• Pistis: Knowledge of physical objects, represented by the firelight and manufactured objects in the cave.

Episteme is divided into:

• Dianoia: Mathematical knowledge, symbolized by the prisoner's initial steps outside the cave, observing reflections in water and the light of the moon and stars. Mathematical entities are reflections of true realities (ideas).
• Noesis: The highest level, intellectual intuition, culminating in the contemplation of the ultimate truth—the Form of the Good.

The Dialectical Method

This epistemological framework must be navigated dialectically. By contrasting opposing entities, the learner eliminates the material and progresses towards greater intelligibility. The aspiring sage ascends through learning, relying on the power of reason.

Plato's dialectic, inspired by the Socratic method, uses questions, answers, and arguments to move beyond concrete examples towards essential definitions. This process of abstraction transcends the particularities of the material world to reach universal concepts in the intelligible realm.

The Ascent and Descent of Knowledge

Once in the intelligible realm, the dialectic continues upwards towards the most fundamental Form, the Form of the Good. However, this ascent must be followed by a descent, as depicted in the allegory of the cave. The wise individual, having achieved noesis, must return to the sensible world, applying their knowledge to human affairs. This descent, a deductive process from universal ideas to the particular, aims to enlighten others, even at personal risk, as exemplified by Socrates' fate. This is the tragic destiny of the wise—the price of wisdom.