In meditation one Descartes contemplates "what can be called into doubt". What he is doing is questioning if what we see and experience is real or if we are being deceived. Perception is something that is our own. The way that one person sees something may be completely different to someone who is standing right next to them. In one passage Descartes questions if beliefs are impossible even though they are derived from the senses. He gives the example of him sitting by the fire in his pajamas writing these meditations and asks the question "how could it be denied that these hands or th…
