Cartesian Doubt, Substance, and Monads in Philosophy

Descartes' Quest for Certainty

René Descartes states that the existence of the thinking self is a truth so strong and secure that even the extravagant assumptions of skeptics were unable to shake it. He argues that from the cogito, ergo sum (I think, therefore I am), there is an intuitive and immediate apprehension of this truth.

The Purpose of Cartesian Doubt

What is the meaning, truth, and purpose of Cartesian doubt? The goal is to achieve a sure and certain knowledge, built by our reason, that can be trusted beyond all doubt.

Descartes' Method: Four Rules

Descartes proposed a methodical approach to acquiring knowledge, consisting of four rules:

1. Rule of Evidence: To accept nothing as true which I do not clearly recognize to be so, avoiding precipitation and prejudgment. Only accept what appears evident with clarity and distinction.
2. Rule of Analysis: To divide each difficulty into as many parts as possible, and as might be necessary for its better resolution.
3. Rule of Synthesis: To conduct my thoughts in such order that, by commencing with objects the simplest and easiest to know, I might ascend little by little, and, as it were, step by step, to the knowledge of the more complex.
4. Rule of Enumeration: To make enumerations so complete, and reviews so general, that I might be assured that nothing was omitted.

Descartes' Criterion of Truth

What is the criterion of truth for Descartes? An evident truth escapes doubt, such as the necessary truth of one's own existence as a thinking subject, even if one is a victim of deception. Clarity and distinctness are the hallmarks of truth.

Descartes on the Innate Idea of God

How is the innate character of the idea of God demonstrated by Descartes? The idea of God cannot be an adventitious idea, as in the physical world we find nothing infinite and perfect. Nor can it be factitious, as such ideas originate from our own thoughts. Therefore, it can only be an innate idea, placed within us by God himself.

Substance: Descartes, Spinoza, and Leibniz

Descartes and Spinoza largely agree on the concept of substance, but Leibniz's philosophy presents a distinct perspective.

• Descartes: Defines substance as that which requires nothing else to exist. He identifies two created substances: thinking substance (mind) and extended substance (matter), in addition to the uncreated substance (God).
• Spinoza: Argues for a single, infinite substance, which he identifies with God or Nature (Deus sive Natura). This substance has infinite attributes, of which we know thought and extension. Its modes are the particular things we perceive.
• Leibniz: Contends that substance is not unique. Instead, there is an infinity of finite substances, which he calls monads.

Leibniz's Monadology

Leibniz's theory of monads posits that substance is not unique; rather, there is an infinity of finite, simple, indivisible substances. These substances are monads, each of which contains or develops a representation of the entire universe from its origin. God establishes a pre-established harmony or perfect correspondence between the representations of all monads, ensuring a coherent universe without direct interaction between them.

Freedom and Evil: Spinoza vs. Leibniz

The philosophers Spinoza and Leibniz offer contrasting views on human freedom and the nature of moral evil.

• Leibniz: Believes that moral evil is a consequence of human sin, resulting from human choice. While God permits evil, it is always in the context of a greater good, as we live in the "best of all possible worlds."
• Spinoza: States that the alleged freedom which humans feel they possess is merely an illusion of the imagination, resulting from ignorance of the true causes determining their actions. For Spinoza, everything is determined by the necessity of God's nature.