Question

René Descartes doubts mathematical knowledge because:

1) He might be dreaming.
2) His senses sometimes deceive him.
3) An evil demon might be deceiving him.
4) All of the above.

Answer 1

René Descartes doubts mathematical knowledge because he considers the possibilities of dreaming, senses deceiving him, and an evil demon deceiving him, all of which would make our beliefs wrong and unjustified. Therefore, the correct answer is (4) "All of the above."

Step-by-step explanation:

René Descartes doubts mathematical knowledge due to the combined influence of options (1), (2), and (3). Descartes introduces radical skepticism in his philosophical method, aiming to establish a foundation of indubitable knowledge. He entertains the possibility that he might be dreaming (option 1), highlighting the uncertainty that dreams can introduce to one's perceptions. Additionally, he acknowledges that his senses can sometimes deceive him (option 2), as sensory experiences are not always reliable indicators of truth. Furthermore, Descartes introduces the famous "evil demon" hypothesis (option 3), suggesting that an omnipotent, malevolent being could systematically deceive him about everything, including mathematical truths. Therefore, the correct answer is (4) "All of the above."