Unit I
IN THIS LESSON
Descartes responds to radical uncertainty with an audacious plan: find one belief so secure that nothing—not even deception itself—can shake it.
Topics Discussed:
The historical and intellectual crises of early 17th-century Europe that shaped Descartes’ project
The motivation behind Descartes’ method of doubt as a response to skepticism
The regress problem and why it pressures philosophers toward foundationalism
Descartes’ strategy of withholding belief from anything that can be doubted
Arguments from sense deception, dreaming, and the evil demon
Why even mathematics and logic become targets of radical doubt
The search for indubitable foundations as the starting point for knowledge
How Descartes’ internal, first-person approach marks a turning point in modern epistemology
Focus Questions
What historical and intellectual conditions made radical doubt feel like a serious philosophical problem rather than a mere thought experiment?
Why does Descartes believe that doubt can be a productive method for achieving knowledge rather than an obstacle to it?
What is the regress problem, and how does it motivate Descartes’ search for indubitable foundations?
How do arguments from sense deception and dreaming challenge our everyday assumptions about knowledge?
Why does Descartes introduce the evil demon hypothesis, and what additional doubts does it raise beyond the dream argument?
What kinds of beliefs survive each stage of Descartes’ method of doubt, and which are eliminated?
Why are mathematical and logical truths not exempt from Descartes’ skeptical challenges?
How does Descartes’ turn inward toward the thinking subject mark a shift in the history of epistemology?
Glossary
Philosophical Concepts and Epistemology
Method of Doubt (or Hyperbolic Doubt): A process used by Descartes to deliberately discard any belief that allows for any possibility of doubt, with the goal of discovering foundational, absolutely certain beliefs.
Foundationalism: The epistemological view that some beliefs are self-justifying (foundational) and serve as the basis upon which all other beliefs are justified; this is Descartes' theory of knowledge justification.
Aristotle's dictum: The principle that one should move from propositions of which they have more confidence to those of which they have less confidence in the process of argumentation.
Regress Argument: An argument that concludes knowledge is impossible because justifiably believing something would require an infinite chain of justified reasons (good reasons are themselves justified beliefs).
JTB Theory of Knowledge: The theory of knowledge that defines it as "justified, true belief".
Key Figures
René Descartes: A pivotal philosopher, mathematician, and scientist of the 17th century, known for inventing Cartesian coordinates and his works like Meditationes de prima philosophia. He is the focus of the lesson and the originator of the Method of Doubt.
John Locke: A thinker mentioned as noticing that religious fanatics could reason just as well as logicians, which contributed to the intellectual focus on religious convictions (the subject of the next lesson).
Giordano Bruno: His burning at the stake in 1600 is presented as an example of a societal event accompanying advancements with a setback.
Galileo Galilei: A figure whose condemnation by the Inquisition is mentioned to contrast his challenge of external authorities with Descartes' method, which was rooted in the individual's mind.
Descartes' Arguments for Doubt (from First Meditation)
Argument from the Senses: The argument that, because the senses have been deceptive in the past, no sensory information is entirely reliable.
Argument from Dreams: The argument that, because there is no reliable way to check if one is currently dreaming, sensory information cannot be fully relied upon.
The Evil Demon Argument: The hypothesis that if it is possible for an all-powerful evil demon to be deceiving him, then even truths known from pure reason (like mathematics), in addition to sensory knowledge, can be doubted.
Historical Context
The Tudor Period (1485-1603): A period in English history typically viewed as a Golden Age, involving monarchs such as Henry VIII, Edward VI, Mary I, and Elizabeth I.
The Thirty Years’ War: A major European conflict that began in 1618, mentioned as part of the chaotic historical background.
Inquisition Condemnation of Galileo (1633): The event where Galileo was condemned to house arrest, showing the challenge to external authorities and motivating Descartes' search for a method rooted in the individual mind.
For other questions…
Reading List
Lorraine Daston & Elizabeth Lunbeck, Histories of Scientific Observation.
René Descartes, Meditations on First Philosophy
Richard DeWitt, Worldviews: An Introduction to the History and Philosophy of Science.
John Greco (Ed.), The Oxford Handbook of Skepticism
Morris Kline, Mathematics for the Nonmathematician
Matt Lawrence, Like a Splinter in Your Mind: The Philosophy Behind the Matrix Trilogy
Michael Shenefelt & Heidi White, If A, Then B: How the World Discovered Logic
Phil Washburn, Philosophical Dilemmas: A Pro and Con Introduction to the Major Questions and Philosophers.
Michael Williams, Scepticism and the Context of Philosophy. Philosophical Issues, 14, 456-475.