---
title: "Descartes’ demon · Library · Simulation Hypothesis"
url: https://simulation-hypothesis.com/library/evil-demon
description: "Descartes’ demon is the all-powerful deceiver Descartes imagined in 1641, who systematically fakes all your experience."
license: https://creativecommons.org/licenses/by/4.0/
credit: "Ross Allan Dahl, Simulation Hypothesis (simulation-hypothesis.com)"
---

## Epistemology & reality

# Descartes’ demon

Definition

Descartes’ demon is the all-powerful deceiver Descartes imagined in 1641, who systematically fakes all your experience. He used it to find out what, if anything, survives radical doubt.

On this site

The operator on a break, in the Slot dial, is a weaker version of the demon on purpose.

Role in the model

Descartes’ deceiver is an early simulation hypothesis, four centuries before the hardware. The operator on a break in the Slot dial is a weaker version of the same figure. The thinker page lays out the argument.

Related

[Skepticism](https://simulation-hypothesis.com/library/skepticism)[Brain in a vat](https://simulation-hypothesis.com/library/brain-in-a-vat)

In the trees

[Suppose you are the only one · Ethics](https://simulation-hypothesis.com/trees/ethics?n=x-alone)

## The people behind the terms

14 short pages, one per thinker, each with its matching dial. See also the [reading list](https://simulation-hypothesis.com/reading).

[Plato’s cave](https://simulation-hypothesis.com/thinkers/plato)[Zhuangzi’s butterfly](https://simulation-hypothesis.com/thinkers/zhuangzi)[Vasubandhu’s dream](https://simulation-hypothesis.com/thinkers/vasubandhu)[Shankara’s māyā](https://simulation-hypothesis.com/thinkers/shankara)[al-Ghazali’s doubt](https://simulation-hypothesis.com/thinkers/ghazali)[Ibn Arabi’s imagination](https://simulation-hypothesis.com/thinkers/ibn-arabi)[Calderón’s life is a dream](https://simulation-hypothesis.com/thinkers/calderon)[Descartes’ demon](https://simulation-hypothesis.com/thinkers/descartes)[Berkeley’s perceiver](https://simulation-hypothesis.com/thinkers/berkeley)[Borges’ circular ruins](https://simulation-hypothesis.com/thinkers/borges)[Nozick’s experience machine](https://simulation-hypothesis.com/thinkers/nozick)[Putnam’s brain in a vat](https://simulation-hypothesis.com/thinkers/putnam)[Bostrom’s trilemma](https://simulation-hypothesis.com/thinkers/bostrom)[Chalmers: virtual worlds are real](https://simulation-hypothesis.com/thinkers/chalmers)