Descartes’ Philosophy: From Doubt to Certainty
Descartes’ Philosophy: Method, Doubt, and Existence
Descartes, before the collapse of Scholastic philosophy, took a stand against skepticism. Skeptics did not believe that knowledge is neat and tidy. His aim was to create a system of knowledge that allows us to know the truth with strength and security. To find these truths, he followed a path called “the method,” which uses reason. This method involves two key activities: intuition and deduction. The method has four rules, the first being the most important:
- Evidence Rule: This is a criterion of truth. An idea is evident when it is clear and distinct. It is clear when it comes to the light of reason and distinct if it comes separately from other ideas, without confusion.
- Analysis Rule: This rule uses intuition.
- Synthesis Rule: This rule uses deduction.
- Reviewing Rule: This rule involves listing in detail all the steps in reasoning to identify possible errors and checking the analysis and synthesis.
Descartes’ Methodological Doubt
Descartes wonders, “What is real?” and “While there, is it real?” But before we know *what* we know, we must know *that* we know. Philosophy cannot accept any principle without a solid foundation, so Descartes sought a foundational principle for philosophy. He begins with what we can *doubt* to arrive at the clear truths of reason. He questions what we have known so far. This questioning involves several things:
- The Senses: Can the senses give us knowledge? This question challenges the Aristotelian conception of knowledge, which relied on the senses as the primary way to gain knowledge.
- The Existence of the External World: Descartes doubts whether what he perceives is real; that is, he doubts the external world. This doubt arises from the difficulty of distinguishing waking from sleep.
- Mathematical Truths: Descartes considered that these might have been created by a being superior to us, who has implanted them in our minds, leading us to be deceived. This is the “evil genius” hypothesis – a powerful being could be deceiving us every time we reason.
“I Think, Therefore I Am”
However, the very act of doubting, of questioning everything, reveals a fundamental truth: the person who is wondering is, therefore, thinking. This leads to the famous statement, “I think, therefore I am” (Cogito, ergo sum), which is the first certainty upon which to build.
Types of Ideas
Descartes starts with his ideas, his thoughts, as the only immediate knowledge he possesses. He identifies three types of ideas:
- Fictitious: These are produced by the imagination from other ideas.
- Adventitious: These seem to come from the outside world.
- Innate: These are inherent in our thoughts.
The Existence of God
By analyzing and discarding ideas, Descartes aims to find those that represent objective reality. He reasons that a more perfect idea must have a cause equal to or greater than its effect. For example, the idea of God could not have been created by us, as we are finite beings. Following the rule of cause and effect, the idea of God must have been created by a being of equal perfection to God. Therefore, Descartes concludes that God exists.
God as Guarantor of Truth
Because God is not a deceiver, we can know that things exist, and God guarantees their existence. However, the problem arises whether sensible things are as we perceive them. Descartes argues that we can only be certain of the *mathematical* properties of things, as these are clear and distinct in our ideas.
Substance and Dualism
Substance, according to Descartes, is that which needs nothing else to exist. This definition applies strictly only to God. However, it can also apply to other beings, which, despite needing God to exist, we perceive only through their attributes.
Descartes’ conception of man is dualistic. Man is composed of mind (thinking substance) and body (extended substance). Both are independent of one another. He rejects the idea that the soul merely animates the body, favoring instead an *interaction* between the two. He located the point of interaction in the pineal gland, which serves as the point of contact between mind and body.