Philx1001 Introduction to Philosophy - the Evil Demon Argument, Its Objection, and Response

Xuyang Gao UNI: xg2236

PHILX1001 Introduction to Philosophy

Professor David Friedell

First paper

The Evil Demon Argument, its Objection, and Response

Descartes demolishes the foundation of his previous beliefs by casting doubts on the credibility of our senses by using the evil demon argument as the foundation for invoking further uncertainties.  It is one of the most radical skepticisms because it reasons that we need to forego all the things that we’ve ever had a doubt about. Descartes introduces the hypothesis that there’s an “all-powerful and deceitful” evil demon who utilizes all its power to deceive him. All he thinks that he knows, “the heavens, the earth, colors, figures, sound, and all other external things” are false and are the illusions created by the demon. Since his senses are deceiving him and his beliefs are formed based on senses, the beliefs are false and thus need to be discarded. This fundamental doubt of the external world is also seen in popular works like the Matrix.

The evil demon argument is of the utmost significance in Descartes’ work. It challenges our cognitive nature- all we think that we know come to us through the senses, however our senses are not reliable. If our senses are not to be entirely trusted, then nothing in the external world is certain, since everything is perceived through our senses. Essentially, our cognitive system is defective. Only after admitting this, Descartes can proceed to the later arguments in Mediation.

To conduct a prudent analysis on the evil demon argument, we need to break down the argument in syllogism, as we’ve discussed in class. The argument proceeds as follow:

        1) I don’t know if an evil demon is making me think that there’s a sky (or any object) when there’s none

2) If I don’t know that an evil demon isn’t making me think there is a sky when in fact there’s none, then there’s no sky

3) So I don’t know there is a sky

The argument is valid. Since the premises 1) and 2) are true, then we can easily arrive at the conclusion that: I don’t know if there’s a sky, where the “sky” could be substituted by anything in the external world. It demonstrates that our senses could be false and that we know nothing about the external world. After all, if we are not certain about one thing in the external world, how can we be certain of another?  .

To construct an objection to this argument, one can start from the following aspects as we’ve discussed in class: the meaningless objection: 1) the words we think they mean isn’t what they mean, such like “demon” and “deception”; 2) the unlikely objection: the likelihood of this situation is very low, thus it may not be true and 3) the skeptics objection: only those who are inclined to skeptic view would be convinced. However, in my opinion none of those arguments are established upon the logic of the argument itself. I think the most interesting objection to the evil demon argument arises from the logic within, especially the second premise.

The best objection from my perspective proceeds as following:

1. If there’s no sky, and the demon is making me think there’s a sky; then the sky I see is not the real sky, since the real sky does not exist
2. If the sky I see is not the real sky, then I don’t know what is a sky/what a real sky looks like
3. So I don’t know what is a sky/what a real sky looks like

I find the evil demon argument to be valid but not sound because of the second premise: “If I don’t know that an evil demon isn’t making me think there is a sky when in fact there’s none, then there’s no sky. ” If the demon is deceiving us, it suggests that we don’t know what a real sky looks like because what we’ve never seen a real sky. What I see is what the demon wants me to see. If a demon makes me think there’s a sky when there’s none→ then my senses are wrong→ I’ve never seen a sky → I don’t know what is a sky. Therefore, I think the argument is unsound because the conclusion is affected by the precondition we use in the first place. The sound conclusion should be: “ I don’t know what is a sky” instead of “ I don’t know if there’s sky.”

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