The Proof of the External World: Cartesian Theism and the Possibility of Knowledge

By Steven M. Duncan

A fastinating analysis of Descartes’ epistemology setting forth a viable theistic approach to the problems of knowledge, in particular of the external world.

ISBN: 9780227172674


Descartes’ attempt to ground the possibility of human knowledge in the existence of God was judged to be a complete failure by his contemporaries. This remains the universal opinion of philosophers to this day, despite the fact that three and a half centuries of secular epistemology – which attempts to ground the possibility of knowledge either in the unaided human intellect or in natural processes – has failed to do any better. Further, the leading twentieth century attempts at theistic epistemology reject both the conception of knowledge and the standards of epistemic evaluation that Descartes takes for granted.

In this book – partly an interpretation of Descartes and partly an attempt to complete his project – the author endeavours to show that a theistic epistemology incorporating Platonic and Aristotelian/Thomist elements can revitalize the Cartesian approach to the solution of the central problems of epistemology, including that most elusive of prizes – the proof of the external world.

This book is essential reading for students of epistemology, metaphysics and philosophy.

Additional information

Dimensions 229 × 153 mm
Pages 244

Trade Information JPOD

About the Author

Dr Steven M. Duncan earned his PhD at the University of Washington in 1987 and has taught at various colleges and universities for the last thirty years. He is currently working at the Adjunct Philosophy Faculty at Bellevue Community College.



1. The Perils of Methodological Doubt
2. The Deceiver Hypothesis
3. Skepticism and the Cogito
4. Thinking
5. Being
6. How Can God Be Apprehended?
7. The Cartesian Cosmological Argument
8. The Concept of God
9. God and Knowledge in the Meditations
10. Descartes’ Arguments for God’s Existence: A Vindication



Endorsements and Reviews

Steven Duncan has produced a rigorous and highly original contribution to one of the greatest philosophical problems of all time. Specialists in Descartes and philosophers doing epistemology will find this book very provocative and original, but The Proof of the External World will also appeal to the general reader interested in the history of philosophy. A wonderful contribution!
Paul Herrick, Professor of Philosophy, Shoreline Community College

Duncan’s essay … creatively reconstructs the arguments of the Meditations by placing Descartes in the medieval itineram mentis tradition as pioneered by Saint Augustine.
Bijdragen: International Journal in Philosophy and Theology, Vol 70, No 4