Descartes’ Philosophy: Existence, Dualism, and the Mechanical World
Descartes: Existence of God and the World
The Ideas and the Idea of God
Descartes realizes that he is a finite and imperfect being, making his own mind aware of its limitations and imperfections. Ideas, according to Descartes, present thought in a double dimension:
- Objective: Ideas are pictures or representations of things.
- Subjective: Ideas, considered in themselves, cannot be false.
Descartes states that there are three kinds of ideas:
- Adventitious: Ideas that come from outside the subject (e.g., sensory experience).
- Factitious: Ideas created or invented by the subject (e.g., mythical creatures).
- Innate: Ideas born within the subject, such as the ideas of infinite existence and substance (God).
Demonstration of the Existence of God
The existence and perfections of infinity are considered God. Descartes cannot conceive of God without existence. God is perfect and infinite. The idea of a perfect and infinite being cannot originate solely from the human mind, since the human mind is finite and imperfect. This idea of perfection is one of the rational philosopher’s key concepts.
The text mentions philosopher Blaise Pascal, suggesting that Descartes believes that those who wish to disregard God need to place the world in a state of contingency. Descartes moves to yet another reason for not disregarding God, stating that the next step is to go from God to the world.
The Extended Substance (The World)
The world consists of bodies (cuerpos). Descartes justifies and demonstrates the essence of existence. The essence of the body is extension, in contrast to thought or the soul, which are unextended.
In analyzing the qualities of bodies, Descartes distinguishes between:
- Primary Qualities: These are the extension of a body (size, shape, motion). They are objective, measurable, and only God guarantees their existence.
- Secondary Qualities: These exist only in the mind (pensamiento). They are subjective (e.g., color, taste, smell) and cause feelings in the subject.
A Mechanistic Approach: Matter in Motion
Descartes explains that the human body functions like a machine. A sick human body is compared to a broken clock, and a healthy body to a good watch. The human body is a substance—matter in motion. Thus, the world is a major mechanism. In this way, the mechanical model unifies the whole of reality.
Descartes explains the behavior of the world, the body, and its components from the perspective of materials being manufactured by humans or by God. The nature of matter is explained in terms of parts and wheels (mechanical components).
Mind-Body Dualism
The Soul and the Body
Body and soul are fundamentally different realities. The body cannot think, and the soul is the essence of the human being, which can exist without the body. Descartes presents a dualistic conception of man:
- The soul as a thinking substance (res cogitans).
- The body as an extended substance (res extensa).
The human being is a union of these two substances, even though they are independent.
Problems of Dualism
Dualism leaves open a significant debate. How can the soul and body interact if they are so different? Descartes responds that the interaction is something we experience and refers the ultimate explanation to God. Descartes wrote The Passions of the Soul to explain how passions influence the body; however, this work did not entirely resolve the fundamental problem of his dualism.
Cartesian Metaphysics
The New Metaphysical System
The Cartesian philosophical system is based on the method (methodological doubt); all metaphysical conclusions proceed from this method. Descartes proposed a new vision of the rational world with a singular perspective: reason is the only guide to accessing knowledge.
The Human Essence: Cogito Ergo Sum
Descartes inferred his existence from the act of doubting. The first metaphysical truth he found was the famous dictum: “I think, therefore I am” (Cogito ergo sum). This established the concept of thought and existence as the primary reference point for knowledge.
The first thing the subject knows is the act of thinking, and then existence. Therefore, “I am a thing that thinks.” Thoughts exist as a substance that takes the form of ideas, which are the contents of thought.