Plato's Dualism: Sensible World vs. World of Forms

The Platonic Conception of Ideas

For Plato, ideas are substantial in nature. Ideas are not produced by independent thought and do not arise from things. Ideas are independent because they have semantic consistency; that is, they have their own meaning no matter what we decide, and when someone knows an idea, it is called the same (because the thought when he sees it is the same), and universal ideas do not arise from particular things.

For Plato, the world is full of thinking beings and things, but as ideas do not come from them, the ideas have to be in another world. He says that in the sensible world, things are finite, mutable, unintelligible, and individual, and this is where we are. While in the world of ideas, things are infinite, immutable, intelligible, and universal. This dualism affects cosmology, epistemology, metaphysics, anthropology, ethics, and politics.

Relationship Between the World of Ideas and the Material World

Epistemological Relationship

Knowing something is to say what something is, and for this, we use the expression "This is such a thing," where an extensional definition "this" is a special case of "this thing," and therefore A belongs to all B. While in an intensional definition, to know that "this" is, first I have to know "such thing," a particular case where A and B are the universal.

Through the rational world, I can get to the intensional definitions and extend the definitions from sensible to extensional. We get to know the ideas through heterogeneity with the experiences and ideas that existed prior to the experience and were contemplated by the immortal soul rather than the body (innate), but have been forgotten at birth when the soul "falls" to the body and are recalled by reminiscence.

To move from the sensible world to the world of ideas is to follow four stages: imagination, belief, discursive reason, and intelligence. These stages are called the epistemological ladder, pursuing the idea of "being, well, beauty," and the ascent is motivated by Eros, which is the desire for perfection that we lack.

Metaphysical Relationship

Plato explains the myth of the Demiurge. This is a chaotic and inert matter, and the Demiurge decided to organize the four fundamental elements, intertwining them to form particles whose shapes can be described by mathematics.

Ethical-Political Relationship

Plato's intellectualism, following Socrates, explains that ethical good is what society rewards and bad is what it punishes. The person who knows the good is good because he understands it and will endeavor not to betray it. Depending on the arrangement of humans for the good, there are three kinds of souls:

• The rational: Related to knowledge and understanding the good, associated with Aristocracy.
• The irascible: Defending the police and public affairs, related to Timocracy (strength).
• The concupiscible: Related to wealth and Oligarchy (temperance).

For Plato, justice is moral enlightenment, and to have a competent government to achieve fairness, we must liberate the immortal soul. We can achieve justice from injustice in a polis where everything is regulated and hierarchical. Plato indicates a decay over time, and this can be seen in government, progressing from aristocracy to timocracy, oligarchy, democracy, and finally, tyranny.