Lecture Notes: Cartesian Skepticism and Rationalism

Introduction

• Focus of lecture: Cartesian skepticism and rationalism.
• Importance of doing readings along with viewing lectures.
• Descartes recognized as one of the earliest modern philosophers.

Descartes and Rationalism

• Metaphysics and Epistemology: Descartes' contributions cover dualism, existence of God, and the nature of knowledge.
• Rationalism: Philosophy that reason is the source of knowledge, involving a priori ideas.
  • Contrasted with Empiricism, which bases knowledge on sensory experiences (a posteriori).
  • Key figures: Descartes (rationalism), Plato (allegory of the cave), and Aristotle (empiricism).

Descartes' Realization of False Beliefs

• Descartes recognized past false beliefs and waited until later in life to investigate them.
• Importance of revising beliefs and replacing false ones with true ones.

Goal of Establishing Certainty

• Descartes aimed to build a stable foundation for human knowledge.
• Employed method of radical doubt to reject uncertain beliefs.
• Sought indubitable truths to serve as a foundation for knowledge.

Descartes’ Method of Doubt

• Cannot doubt each belief individually due to sheer volume.
• Focused on doubting foundational beliefs.
• Called sense perceptions into doubt, considering the possibility of dreaming or insanity.
• Introduced the possibility of an evil demon deceiving him.
• Rejected beliefs that could be doubted.

Moving from Doubt to Certainty

• Dream Argument: Recognized that dreams can mimic reality, casting doubt on sensory-based beliefs.
• Evil Demon Hypothesis: Proposed that an evil genius could deceive him, leading to skepticism about existence of the external world.

"Cogito Ergo Sum" (I Think, Therefore I Am)

• Even in doubt, Descartes concluded he must exist as a thinking entity.
• Established thinking as the foundation for knowledge.

Rebuilding from Certainty

• Followed with arguments for the existence of God using the Ontological Argument.
• Proposed that a benevolent God ensures senses are generally reliable.

Impact of Descartes' Work

• Descartes' ideas challenged by the Church, viewed as elevating human reason over divine revelation.
• Contributions helped usher in the scientific revolution by advocating for empirical study of the physical world.

Upcoming Topics

• Future discussions will include Cartesian dualism and arguments for the existence of God.

Conclusion: Descartes' method of doubt and his pursuit to build a firm foundation of knowledge remain influential in philosophy and the development of modern science. His work encourages the separation of empirical study from spiritual doctrine.