Philosophy Test Review #2
Many of our beliefs are based on sensation. Descartes offers two arguments— the arguments from deception and dreaming—to show that beliefs based on sensations are not trustworthy. State these arguments in your own words?
(1) Argument from deception: If the senses have deceived us in the past, then they may be deceiving us now. The senses have deceived us in the past, therefore they may be deceiving us now. (2) Argument from dreaming: If we cannot be certain we are not now dreaming, then we may be dreaming.
Descartes ended the first Meditationwith the famous evil demon argument. What is the point of this argument?
All our beliefs about an external reality may be false because it is always possible that an evil demon is constantly working to deceive us about what is real.
Descartes concludes that the statement "I am, I exist" must be true whenever he thought it. Why? What reasons support this conclusion?
Answer: If I am doubting the existence of everything I once took to be real, then I cannot be doubting my own existence without presupposing, in the very act of doubting, my existence. To doubt is to think and to think is to exist. Likewise, if I am being deceived, then I am thinking, and thinking that I am something, namely, someone who is being deceived
The next step in Descartes's argument is to reach the conclusion that he is a thinking thing. How does he reach that conclusion? Why does he not conclude instead that he is a physical thing?
He comes to this conclusion by saying thought can't be taken from him. He doesn't conclude that he's a physical thing because he's not just a collection of organs called a human body.
What is Descartes's goal, and what method did he employ to get there?
His goal is to find a stable, lasting, and certain (indubitable) foundation for knowledge. His method is to subject the foundations of his present beliefs to doubt in order to see which can be trusted and which cannot
In the final paragraph of Meditation II, Descartes listed several things he had learned from his consideration of a piece of wax. What are they, and how did he arrive at these conclusions?
I now know that physical objects are grasped, not by the senses or the power of having mental images, but by understanding alone. And, since I grasp physical objects in virtue of their being understandable rather than in virtue of their being tangible or visible, I know that I can't grasp anything more easily or plainly than my mind. He comes to this conclusion by saying the way you grasp a piece of wax or any other physical object serves better to reveal the nature of my mind.
Some of our beliefs―for example that two plus three equals five―are based on reasoning, not sensation. Descartes argues that even arithmetic calculations can be doubted. What is his argument?
It is possible that God may deceive me when I count or add or reason mathematically. Hence, while I believe I am adding correctly, I may not be. Make sure the students understand that Descartes is not claiming that "two plus two equals four" and the like are false, only that it is possible to be deceived when calculating.
