Plato’s Theory of Ideas: Two Worlds and the Path to Knowledge
Plato’s Theory of Ideas
The theory of ideas is the core of Platonic philosophy. Plato advocated an ontological dualism, believing in the existence of two kinds of reality or types of worlds: the sensible and the intelligible world, or world of ideas.
The Two Worlds
Sensible World: Particular reality characterized by multiplicity, change, destruction, generation, and all things perceptible to the senses; things material, temporal, and spatial.
Intelligible World: Universal realities not subject to change; they are eternal, invisible, immaterial, and are known by reason. Ideas are the causes of things. Plato, unlike Parmenides, does not deny the existence of the senses (sensory world). The world of Ideas consists of different types of ideas, not all valued the same way. The Idea of Good, moral ideas, and others. Plato puts mathematics at the top of the intelligible world, sometimes identifying it with the idea of beauty and even with God. The Idea of the Good is real because human behavior aims to view it, and everything tends towards it.
Knowledge: Science and Opinion
Plato divides reality and knowledge into two distinct categories:
- Science: Deals with the Ideas; it is permanent.
- Opinion: Knowledge of the sensible world, subject to generation and corruption, divided into belief and conjecture.
Within Science, Plato distinguishes discursive thought and dialectic:
- Discursive Thought: Primarily identified with mathematics (geometry and arithmetic).
- Dialectic: The superior knowledge, referring to the World of Ideas, to the immutable and universal, eternal; identified with philosophy. Plato conceived of it in two ways: as a rational method using no sensible signs, employing only reason and ending in the Idea of the Good; and as an erotic impulse: the philosopher’s rise from the sensible to the intelligible, an intellectual and emotional ascent ending in the Idea of Beauty.
Man and the State
Plato conceives of man as a composite of two distinct substances: the body, which links us to the sensible world, and the soul, which connects us to the upper world.
Theory of Reminiscence: Plato defends the thesis that knowing is remembering; knowing is updating experienced knowledge.
Philosopher King: Plato believed, as a good Greek, that man is by nature a social being, which explains the appearance of the state (Polis). The individual can reach their full realization in the state, but the State must be perfect. The philosopher has to be the ruler, or rulers should be philosophers, seeking not to satisfy their own interests but the community’s as a whole.
Key Concepts
Intelligible World: An inaccessible world inhabited by perfect models that serve as a guide to the things of this world, explained through the myth of the cave. It is a perfect, unchanging world where souls reside, opposed to the sensible world of material copies.
Dialectic Method: A method of knowledge based on dialogue and questions to arrive at the truth. It involves irony (questions to reveal ignorance) and maieutics (guiding others to knowledge).
Idea of the Good: The perfect model of good, the most perfect idea in the world of Ideas, serving as a model for people and behaviors, though it cannot be known directly in the sensible world.
Philosopher King: The best men, those who use reason, whose mission is to teach, transmit knowledge, and govern, as they are closer to understanding goodness and justice.
Reminiscence: The process of knowing as remembering; recalling the knowledge our souls had in the world of Ideas.
Plato: Life and Context
Plato was an Athenian with a stormy life, dying at 82, a high life expectancy for his time. He came from one of the richest families in Athens. He considered education to be the same for both men and women, making him, in modern terms, a proto-feminist. His universalism sought absolute, perfect, and universal ideas defining each thing, emphasizing mathematics as a path to truth.