IN THIS LESSON

If our senses can deceive us and our reasoning can outrun experience, which should we trust as the true foundation of knowledge: reason alone, or the evidence of the world?

Topics discussed:

  • How radical skepticism (including modern versions like simulations) motivates Descartes’ turn inward

  • A reconstruction of René Descartes’ Cogito argument as a proposed foundation of certainty

  • The difficulty of moving from Descartes’ foundational truths to knowledge of the external world

  • Philosophical objections to Descartes’ inference from thinking occurs to a unified self exists, including Nagasena’s chariot analogy

  • The role of innate ideas and God in Descartes’ attempt to bridge the epistemic gap

  • John Locke’s rejection of innate ideas and the blank slate hypothesis

  • Locke’s empiricism, including simple vs. complex ideas and indirect realism

  • The tension between reason and the senses as competing sources of knowledge

  • The emerging dilemma between rationalism and empiricism as rival epistemic frameworks

Focus Questions

  • How is the Simulation argument like a modern-day evil demon argument?

  • How does the Cogito argument respond to radical skepticism, and what exactly does it succeed in proving?

  • Does the fact that thinking occurs require the existence of a unified, substantial self — or only thoughts? Explain, as best you can, the challenge from Nagasena’s chariot analogy.

  • Why does Descartes think God is needed to secure knowledge beyond the Cogito, and why has this move been controversial?

  • What is Locke’s argument against innate ideas, and how does it undermine key assumptions in rationalism?

  • What are simple and complex ideas?

  • How does Locke’s empiricism lead to a more modest view of what we can know with certainty?

  • In what sense does empiricism trade certainty for reliability, and is this a reasonable exchange?

  • Both Descartes and Locke were each interested in providing a counterbalance to religious fanaticism, albeit they took different approaches and had different aims: Descartes attempted to reconcile faith and reason, and Locke tried to convince his readers that we can’t view 100% about our views on reality. How did each try accomplish their goals?

Reading List

Princess Elisabeth of Bohemia, René Descartes, & Lisa Shapiro (Translator), The Correspondence between Princess Elisabeth of Bohemia and René Descartes.

René Descartes, Meditations on First Philosophy

John Greco (Ed.), The Oxford Handbook of Skepticism

Matt Lawrence, Like a Splinter in Your Mind: The Philosophy Behind the Matrix Trilogy

John Locke, An Essay Concerning Human Understanding.

Phil Washburn, Philosophical Dilemmas: A Pro and Con Introduction to the Major Questions and Philosophers.

Keith Yandell, Philosophy of Religion (2nd Edition).