Descartes’ Epistemology: Understanding His Theory of Knowledge
Descartes’ Epistemology: Theory of Knowledge
Descartes had a great interest in thinking about man, the self, and introspection. Everything started from scratch as a result of discovering errors in established knowledge. Heliocentrism, showing the existence of an infinite universe without a center, conditioned philosophers to review all criteria of truth. This period of doubt caused great confusion and uncertainty, leading to the school of thought known as Rationalism. Its main features are:
- Reason is the only source of true knowledge.
- The goal is a rational and universal philosophy uniting everyone.
- Mathematics is used as the sole form of knowledge.
Descartes believed that the primary goal of philosophy was to find a new method to distinguish truth from error. He thought that, through mathematics, he could create a universal philosophy. From there, he established the foundations of analytic geometry, creating a universal method of knowledge. The rules of this method (inductive and deductive) are:
- Rule of Evidence: Accept nothing as real until it is a clear and distinct thought that generates no doubt.
- Rule of Analysis: When presented with a problem, divide it into its difficulties to simplify and grasp, by intuition, the simplest truths.
- Rule of Synthesis: Deductively lead from the simplest truths to the most complex.
- Rule of Enumeration/Review: The processes of analysis and synthesis must be reviewed several times.
Descartes applied this method and searched for a first truth that must be simple and clear (Evidence). To find this first truth, he applied methodical doubt; that is, everything is in doubt until an idea is found that cannot be doubted (Rule of Analysis). Descartes’ doubt is:
- Universal, because it applies to everything.
- Voluntary.
- Methodical, for studying theoretical knowledge.
- Provisional.
Descartes applied his doubt according to the following levels:
- The Fallacy of the Senses: Can we trust our senses? If our senses have led us to confusion even once, we should not rely on them. Therefore, through the senses, we cannot obtain a truth that cannot be doubted.
- The Impossibility of Distinguishing Wakefulness from Sleep: Although we may think something is real, we could have dreamed it.
- The Evil Genius Hypothesis: Descartes posited the possibility of an evil demon, a god who entertains himself by creating a total lie, deceiving us.
The only thing that cannot be doubted is the existence of thought (“I think, therefore I am”), because it is clear and distinct. All ideas could be false, but the act of thinking cannot be doubted.
Descartes and Idealism
Descartes also developed, and then discarded, Idealism. The existence of reality had become a philosophical problem. Descartes stated, “I think, therefore I am,” meaning that the “I” is a thinking substance. He used “substance” to mean that which exists by itself. Therefore, the soul is immortal and exists independently of the body. The individual is clear that there is thought or soul, and not his body. This is called Solipsism, which begins with the assertion that thought is clearly evident and distinct.
Thought has classified ideas:
- Adventitious Ideas: Ideas that come from outside, through the senses.
- Factitious Ideas: Ideas constructed by thought, which may be false.
- Innate Ideas: Ideas that have not been created, are very simple, and are what solipsism claims.
The Existence of God
The best idea is the existence of God, and to demonstrate this, Descartes argued:
- If the idea of God is a maximum, God must exist.
- If the idea of perfection is in my mind, this must be God because my mind is finite.
- If the idea of perfection is in my mind, I would not have that perfection.
Thus, Descartes affirmed the existence of thought and of God. This negates the idea of an evil genius and also implies a world outside. So, the world metaphysically derived by Descartes is a geometric world of bodies, movement, and mathematics.