Position
External-World Skepticism
We cannot know that an external world exists, because no experience rules out that we are dreaming or being deceived.
Classification
- Position level
- specific
- Domains
- Epistemology
Overview
Descartes raised the doubt as a first step to be later overcome, but taken on its own it names a durable skeptical position: since any course of experience could in principle be a dream or the work of a deceiver, no perceptual belief about mind-independent things is ever certain. Modern versions replace the deceiver with the brain-in-a-vat, but the structure is the same — the skeptical scenario cannot be ruled out from the inside.
Position on
- Knowledge of the External World
Even granting that some truths survive doubt, beliefs about a mind-independent world do not, because the dreaming and deceiver scenarios are subjectively indistinguishable from waking veridical experience.
Broader position
Incompatible positions
- Moorean Common Sense
Question scope: Knowledge of the External World
References
- René Descartes, Meditations on First Philosophy, Meditation I
- René Descartes, Meditations on First Philosophy, Meditation I (the dreaming and evil-deceiver doubts)
- G. E. Moore, 'Proof of an External World', Proceedings of the British Academy 25 (1939), which claims the knowledge of external things that the skeptical conclusion denies
- Stanford Encyclopedia of Philosophy, Skepticism