Plato and Aristotle: Contrasting Theories of Knowledge
Plato’s Theory of Knowledge
Plato grounds his theory of knowledge in his theory of Forms (or Ideas). He posits that true knowledge is achieved through the Dialectic, a method sensitive to the intelligible realm of Forms.
The World of Forms
For Plato, the Forms are independent realities, the true objects of knowledge. He distinguishes between two worlds: the world of Forms, representing true reality, and the world of shadows (our perceived reality).
The Role of the Soul
Our souls perceive the sensible world through our senses, but the senses cannot grasp the truth. Plato argues that absolute and objective truths cannot be derived from sensory experience. True knowledge originates from the realm of Forms, which are eternal, uncreated, and immutable.
Recollection and Prior Knowledge
Plato suggests that the soul possesses knowledge from a prior existence. Learning, therefore, is a process of recollection, where the soul remembers what it contemplated in the afterlife before incarnating in a human body.
Faculties of Knowledge
Plato identifies two faculties of knowledge:
- Rational Knowledge: Derived from discursive thought and pure science (Dialectic).
- Opinion: Based on sensations, leading only to opinion, not truth. Opinion has degrees: illusion (imagination) and belief.
Real science arises only from the Forms. Plato acknowledges that Forms encompass values (equality, justice) and natural things (water, fire). A Form is a unique entity that can be manifested in multiple instances.
Participation and Imitation
The relationship between Forms and particular things is characterized by participation and imitation. Things participate in Forms, implying that Forms are involved in them. Alternatively, things imitate Forms, acting as copies of the models.
Aristotle’s Theory of Knowledge
Unlike Plato, who views knowledge as a recollection of the soul’s prior experiences, Aristotle emphasizes the role of sensory experience. He rejects the notion of a pre-existing soul and argues that knowledge is built upon the data provided by the senses.
Empirical Foundation
Aristotle asserts that nothing exists in the understanding that was not first in the senses.
Levels of Knowledge
Aristotle identifies different levels of knowledge:
- Sensation: The lowest level, shared by animals and humans.
- Memory: Some animals possess memory of sensations.
- Imagination: An extension of perception.
- Experience: Arises from the rational coordination of sensations.
- Art and Science: The ability to comprehend and understand.
The Role of Imagination
Imagination allows for the mental reproduction of objects in their absence, facilitating understanding (the ability to think and judge), which is the foundation of science.
Active and Passive Intellect
Aristotle distinguishes between two principles in the intellective soul:
- Active Intellect: Immortal and eternal, abstracts forms from things.
- Passive Intellect: Receives forms and generates universal concepts of science.
Hylemorphism and the Soul
Aristotle’s hylemorphism addresses the problem of knowledge by positing an immortal and eternal active intellect, while the passive intellect is corruptible and mortal.
Rational and Irrational Soul
Aristotle divides the soul into rational and irrational parts.
Departure from Plato
Aristotle departs from Plato by viewing the soul as being of the same nature as the body. He suggests that the soul enters the body from the outside and is created at the time of conception.