The Platonic Soul
The Platonic Forms
Epistemic Questions
- What are the objects of knowledge?
- How is knowledge possible?
- What is the difference between knowledge and belief or opinion?
Metaphysical Questions
- What is real?
- How is it that two different things can have some thing in common?
- Is reality fundamentally permanent and unchanging or fundamentally impermanent and changing?
Plato's Answer
Distinguish between the (impermanent and constantly changing) world we perceive and the (permanent, unchanging) world which is intelligible but not perceptible by postulating the existence of Forms. For example, the thing two red apples share is the form of redness. They partake of the form of redness. Presumably for each property there is a Form of that property.
Plato argues that the Forms are, among other things,
- Divine
- Eternal
- Intelligible
- Imperceptible
- Unchangeable
Plato has a number of arguments for the existence of the Forms. For example, in The Phaedo, 74-76, Plato gives the “Equal Sticks Argument”:
| The Equal Sticks Argument | |||
| 1 | If we can judge that no two sticks are perfectly equal, then we have the idea of perfect equality. | ||
| 2 | We can judge that no two sticks are perfectly equal. | ||
| ∴ | 3 | We have the idea of perfect equality. | 1&2 |
| 4 | If we have the idea of perfect equality, then the Form of equality exists. | ||
| ∴ | 5 | The Form of equality exists. | 3&4 |
The (Radically Simplified) Divided Line
| Epistemology | Metaphysics |
| Knowledge | Forms |
| Opinion | Appearances |
The Tripartite Soul
In The Phaedo, Plato argues that the soul shares some of the attributes of the Forms. “The soul is most like that which is divine, immortal, intelligible, uniform, indissoluable, and ever self-consistent and invariable, whereas body is most like that which is human, mortal, multiform, unintelligible, dissoluable, and never self-consistent.”
However, the soul that is embodied acquires differentiable aspects. Specifically, the embodied soul is distinguishable into three aspects:
The Rational
That aspect of the soul responsible for thought, reason, deliberation, and inquiry.
The Passionate
That aspect of the soul responsible for passion, love, and spirit.
The Appetitive
That aspect of the soul responsible for (bodily) desires.