First, he threw away his senses because he couldn't trust them. He stated that they can be deceptive, but to be deceived it must exist. Therefore, Descartes concludes that the only way to prove its existence is through thought. Descartes wrote “thought, this alone is inseparable from me, I am, I exist. - it is certain” and it should no longer exist once it stops thinking (p. 18 p 27.) According to Descartes to exist and be certain of our existence we must be a thing which “doubts, understands, affirms , denies, wants, does not want, also imagines and has sense perceptions” in the end we must be intellectuals and not go with the flow of our deceptions.