PHILOS 21Skepticism and Rationality
Philosophy · 5 units · Undergraduate lower division (0-99)
Can we know anything with certainty? How can we justify any of our beliefs? Introduction to study of these and related questions through works of some great philosophers of modern period, such as Descartes, Hume, Leibniz, or Berkeley.
P/NP or letter grading.
When it runs
- Spring 2026
- Spring 2027
Scheduled, not typical — from UCLA’s Schedule of Classes, which publishes Fall 2025 through Spring 2027 and nothing before it.
Requisites
UCLA lists no requisites for this course.
Requires
Everything that has to come before this course, not just the courses named in the requisite above.
Nothing — this is an entry point.
Unlocks
What this course is a requisite for, and what those courses lead to in turn.
PHILOS 21
- PHILOS C109Descartes
- PHILOS C111Leibniz
- RELIGN M175Topics in Philosophy of Religion
- PHILOS C115Kant
- PHILOS 174Topics in Theory of Knowledge
- PHILOS M175Topics in Philosophy of Religion
- PHILOS 182Elements of Metaphysics
- PHILOS 183Theory of Knowledge
- PHILOS 184Topics in Metaphysics
- PHILOS C215Kant
10 courses list this as a requisite. The whole downstream is here — 10 courses over 1 level. Every course here opens its own tree.