Plato’s Two Worlds: Ideas and Senses
Ontology and Epistemology: Plato’s Two Worlds
In his view of reality, Plato distinguishes between two worlds: the intelligible world of Ideas, which is truly real and not perceived by the senses, and the sensible world, which consists of things perceived by the senses, ultimately copies of Ideas. Ideas are the authentic reality, characterized as eternal, immutable, rational, and ideal. They are the models from which the Demiurge constructs the sensible world. These two worlds have distinct characteristics: Ideas are unique, eternal, immutable, and immaterial, while the sensible is multiple, perishable, changing, and material. The Idea gives things their being, essence, and the possibility of knowledge. Within the world of Ideas, there is a hierarchy: from mathematical ideas to beauty and justice, culminating in the Idea of Good, likened to the sun, which gives life to material things in the sensible world. Good is the ultimate principle of reality and the foundation of knowledge.
Ontological and Epistemological Dualism
Plato believed reality is divided into two worlds, the Material (MOH) and Intelligible (MI), a division called ontological dualism.
The Sensible World (MS) comprises objects within our view, with finite lives, born and dying, imperfect compared to the eternal perfection of Ideas. This leads to the Intelligible World, the absolute reality of Ideas, unchanged over time, the models for sensible objects. These objects are analyzed not by our senses but by our rational side.
For Plato, a philosopher’s task is to journey from the sensory world to the world of Ideas, contemplating the Idea of Goodness. This ascent is paralleled by epistemological dualism, distinguishing two levels of knowledge. Scientific knowledge provides a clear, objective view of reality, achieved by setting aside senses and appearances, as absolute knowledge comes only through Ideas. The second is opinion, relative knowledge based on changing sensible objects, incapable of providing absolute knowledge. The Visible World is the set of things appearing to the senses, characterized as temporary, spatial, changing, and corruptible. Our body is part of this material world. The Sensible World is not mere opinion but can be studied scientifically. In the myth of the cave, it is represented by the world inside the cave. Sensible World things exist by participating in or imitating the eternal world of Ideas. This world is made (not created) by the Demiurge, modeled on the Intelligible World. This is a physical world, perceived by our senses, reflecting Ideas imperfectly. Wisdom, for Plato, is the highest virtue, parallel to the upper class in the ideal city and the highest part of the soul.
Simile of the Line (Epistemology)
Through the simile of the line, Plato explains the degrees of knowledge, a journey from ignorance (darkness) to ultimate knowledge or Ideas (light). There are four stages or degrees of knowledge, divided between the world of the senses and the world of Ideas. The world of the senses includes imagination, the lowest degree, and belief, knowledge of sensible things through intuition. These form opinion (doxa), not true knowledge. The world of Ideas includes thought (dianoia), knowledge of mathematics, and intelligence (noesis), knowledge of ultimate Ideas through intuition, leading to the Idea of Good.
Myth of the Cave
In the myth of the cave, men chained since childhood see only shadows on the cave wall, projected by models passing before a fire. One escapes, facing the difficult journey to the outside world, initially blinded by sunlight. Gradually adapting, he realizes the shadows were illusions. Returning to the cave, he is dismissed as mad by those who believe only in the shadows. Plato uses this myth to explain the human condition and the world of Ideas. The cave’s shadows symbolize the sensible world, mere reflections of true reality. The escape represents the transition to the Intelligible World, a difficult path to higher knowledge. The outside world is the world of thought, the Ideas, with the fire representing the Idea of Good. Prisoners symbolize souls trapped in the sensible world, their chains the body. The escapee is the philosopher, who intuits Ideas, often scorned by others. Plato establishes a dualistic reality: the sensible world is imperfect and ephemeral, while the Intelligible World of Ideas is perfect, eternal, and immutable, accessible only through philosophical insight.