Descartes’ First Meditation • Four bulldozers of doubt: – I can’t trust my senses – I could be crazy – I could be dreaming – A malicious demon could be out to fool me. • Is there anything you’d stake your life on?
Descartes’ Second Meditation • • • • • Is there anything I can’t doubt? I can’t doubt that: I doubt. Try it: I doubt that I doubt. OK, but then: I doubt that I doubt. Self-certifying process: Doing it makes it so. • So, “I doubt” is absolutely certain.
Evaluating Descartes’ Argument: • If I am dreaming, or the evil genius is deceiving me--then there is a “me” that is being deceived! • But “I” exist, only as a thinking thing. He hasn’t proven the existence of his body. • Has he proven that you exist, as a thinking thing?
Evaluating Descartes’ Argument: • • • • • Only proves his own existence: “Solipsism” (solus=alone + ipsi=self). The Problem of “Other Minds”. You have to prove your own existence. Who/What else can prove their own existence?
Evaluating Descartes’ Argument: • Are you absolutely certain that he exists? • What kind of proof is that? • Doesn’t a proof have to convince everyone? • A proof has to be objective. • Descartes’ proof is subjective.
Evaluating Descartes’ Argument: • We know with absolute certainty that there is doubting and thinking. • But do we know with absolute certainty that there is a unified consciousness that is doing the thinking?