Plato’s Philosophy: Epistemology, Anthropology, Ethics, and Politics
Plato’s Theory of Knowledge (Epistemology)
In Theaetetus, Plato concludes that knowledge cannot be mere perception. He asserts that varying degrees of knowledge correspond to different degrees of reality. As Socrates argues, true knowledge is infallible. Since the sensible world is fallible and constantly changing, knowledge cannot be derived from it. While Plato accepts Protagoras’ relativism in that we all perceive our own reality, he disagrees that perception equates to knowledge. He posits that the mind must act upon perception to attain knowledge. Knowledge is not simply a true belief, even with an explanation, as particular objects are unidentifiable because they are not the subject of true knowledge. In the Republic, Plato states that the true object of knowledge is universal, eternal, immutable, and infallible, like the Being of Parmenides.
Plato’s Anthropology: The Nature of Man
Plato views man as a spiritual soul separate from, yet connected to, the body. The soul is the most valuable part of man and must be cared for, with a focus on truth. This is a dualistic view, separating body and soul. In his works, such as The Laws, he describes the soul as the principle of movement. In Timaeus, he states that the soul is the only existing thing that is intelligent and invisible. In Phaedo, he argues that the soul is distinct from the harmony of the body. In the Republic, he distinguishes three functions of the soul:
- Rational: The immortal part that distinguishes us from animals.
- Irascible: The seat of passions.
- Concupiscible: The source of human appetites.
In Timaeus, he locates these functions in the body: rational in the head, irascible in the chest, and concupiscible in the belly. He states that the irascible and appetitive parts die with the body, while the rational soul is immortal. In Phaedrus, he compares the soul to a chariot driven by two horses: the rational soul drives, while the horses represent the irascible (good) and appetitive (bad) functions.
The Immortality of the Soul
Plato offers several arguments for the soul’s immortality:
- In Phaedo, he argues that opposites generate each other; life produces death and vice versa, forming a cyclical process in the universe.
- A priori knowledge suggests the pre-existence of the soul before the body.
- In Phaedo, he explains that the soul is simple, unlike composite, sensitive things that dissolve.
- The soul contemplates eternal, immutable ideas, suggesting it is immortal, similar to what it knows.
- The soul is immaterial and spiritual, thus indestructible. The idea of a sensible thing does not affect the idea of its opposite. The soul shares the idea of life and is incompatible with death. When the body dies, the soul departs.
- In the Republic, he argues that sensible things are destroyed by inherent evils. The soul’s inherent evils are intemperance, injustice, ignorance, and cowardice. However, these do not destroy the soul, so nothing external can.
Plato’s Eudemonistic Ethics
Plato’s ethics are eudemonistic, meaning that the supreme good is happiness. In Philebus, he states that happiness is a state of mind. It cannot be achieved solely through sensible pleasures or intellect alone. A good life must be a balanced mix, including both real-world and intellectual pleasures, excluding those that are evil. Knowledge of God is essential for the soul’s immortality. Happiness is achieved through the practice of virtue. Each part of the soul has a corresponding virtue:
- Wisdom: Rational soul
- Fortitude: Irascible soul
- Temperance: Concupiscible soul
Exercising these virtues leads to a just life. We should not be deceived by the appearance that evil brings benefit. In Gorgias, he criticizes the idea that nature dictates the weak are dominated by the strong. Leaders must know the idea of good to prevent the city’s destruction.
Plato’s Political Philosophy
Plato’s political philosophy is closely related to his ethics. He believes that man is social by nature, and the state’s morality depends on the morality of its individuals. The state is not an arbitrator or source of justice. His political works include the Republic, The Statesman, and The Laws. He proposes a theory of the Polis, where individuals exist to produce and live together. Each person has specific skills and should focus on one task:
- Artisans: Produce goods, dividing labor and specializing.
- Guardians: Possess courage, know the state’s enemies, and are trained in music and gymnastics.
- Rulers: Selected from the guardians, they have experience and prioritize the common good. They cannot possess wealth or power.
Each group corresponds to a virtue: prudence for rulers, fortitude for guardians, and temperance for artisans. When each class fulfills its role, justice reigns. Plato advocates for the community of women and children among the guardians to maintain order in the Polis. He considers democracy absurd, believing that not just anyone should rule. Rulers should be trained in music, gymnastics, mathematics, and astronomy.