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13. Knowledge Criteria / D. Scepticism / 4. Demon Scepticism

[experience is virtual reality from demon/scientist]

3 ideas
God may have created nothing, but made his creation appear to me as it does now [Descartes]
     Full Idea: How do I know that God did not bring it about that there is no earth or heavens, no extension, shape, size or place, and yet that all these things appear to me precisely as they do now?
     From: René Descartes (Meditations [1641], §1.21)
To achieve full scepticism, I imagine a devil who deceives me about the external world and my own body and senses [Descartes]
     Full Idea: I will suppose an evil genius, supremely powerful and clever, who has directed his entire effort at deceiving me. I will regard all external things as devilish hoaxes, and myself as not possessed of a body or senses, but falsely believing these things.
     From: René Descartes (Meditations [1641], §1.22)
An evil scientist may give you a momentary life, with totally false memories [Unger]
     Full Idea: The evil scientist might not only be deceiving you with his electrodes; maybe he has just created you with your ostensible memory beliefs and experiences, and for good measure he will immediately destroy you, so in the next moment you no longer exist.
     From: Peter Unger (Ignorance: a Case for Scepticism [1975], 1.12)
     A reaction: This is based on Russell's scepticism about memory (Idea 2792). Even this very train of thought may not exist, if the first half of it was implanted, rather than being developed by you. I cannot see how to dispute this possibility.