My latest take on Descartes' Evil Demon Argument
I shall consider the following argument for skepticism:
(1) Either (a) I see that I have hands or (b) it merely seems to me that I have hands because I’m deceived by Descartes’ evil demon.
(2) According to the skeptic, whenever I seem to see that I have hands, it is always logically possible that I’m deceived by Descartes’ evil demon.
(3) Hence I can never really know for sure whether I really have hands.
Premise (2) is justified by the assumption that (a) and (b) are subjectively indistinguishable states of consciousness (an assumption which I shall not dispute), from which it seems to follow that no one could ever be entitled to believe that he's in state (a) rather than (b).
I believe, however, that premise (2) is inconsistent with premise (1), and so if (1) is true (and it's hard to see how it could be false, since (a) and (b) seem to be the only two relevant possibilities), it follows that (2) must be false. If now we combine premises (1) and (2) it seems that we must arrive at the following conclusion:
(*) Whenever it seems to the subject that he's in state (a), it is always possible for him to actually be in state (b).
But (*) is incoherent. For it says that it's a logical possibility for an (a) state to be a (b) state, which is plainly absurd since (a) and (b) logically exclude one another. If I see truly that I have hands (a), it logically excludes my being in error (b), for it is impossible for me to have hands and also be a handless person deceived by the evil demon.
And this shows that the skeptic cannot assume that it is always possible for the subject to be in state (b), unless he can show that he is actually in that state--which of course he cannot do, since obviously no skeptic would claim to know that we are in fact being deceived by the evil demon. And so it follows that one cannot derive the radical possibility of skeptical error about our ordinary beliefs concerning the external world, from the mere subjective indistinguishably of veridical and non-veridical states of consciousness.
What do you think?
(1) Either (a) I see that I have hands or (b) it merely seems to me that I have hands because I’m deceived by Descartes’ evil demon.
(2) According to the skeptic, whenever I seem to see that I have hands, it is always logically possible that I’m deceived by Descartes’ evil demon.
(3) Hence I can never really know for sure whether I really have hands.
Premise (2) is justified by the assumption that (a) and (b) are subjectively indistinguishable states of consciousness (an assumption which I shall not dispute), from which it seems to follow that no one could ever be entitled to believe that he's in state (a) rather than (b).
I believe, however, that premise (2) is inconsistent with premise (1), and so if (1) is true (and it's hard to see how it could be false, since (a) and (b) seem to be the only two relevant possibilities), it follows that (2) must be false. If now we combine premises (1) and (2) it seems that we must arrive at the following conclusion:
(*) Whenever it seems to the subject that he's in state (a), it is always possible for him to actually be in state (b).
But (*) is incoherent. For it says that it's a logical possibility for an (a) state to be a (b) state, which is plainly absurd since (a) and (b) logically exclude one another. If I see truly that I have hands (a), it logically excludes my being in error (b), for it is impossible for me to have hands and also be a handless person deceived by the evil demon.
And this shows that the skeptic cannot assume that it is always possible for the subject to be in state (b), unless he can show that he is actually in that state--which of course he cannot do, since obviously no skeptic would claim to know that we are in fact being deceived by the evil demon. And so it follows that one cannot derive the radical possibility of skeptical error about our ordinary beliefs concerning the external world, from the mere subjective indistinguishably of veridical and non-veridical states of consciousness.
What do you think?
Comments (48)
As a retort: but this is false: if an evil demon does in fact deceive you, then it is impossible that you are actually seeing your hands. Thus, the realist cannot assume that (2b) is true, where (2b) is that it is always logically possible that you are actually seeing your hands and are not deceived.
In other words I believe your argument is question-begging. Descartes' evil demon argument is aimed precisely at this epistemological ambiguity - the experience of seeing our hands is compatible with both hypotheses, and thus it cannot be assumed that one hypothesis is right.
I'm not sure what you mean here by "always logically possible". Surely if it seems to me that I see my hands, then it IS logically possible that I see my hands, if I in fact have them and am not deceived. Do you reject premise (1)?
What is wrong with the skeptical argument is that if premise (1) is true, then it's simply incoherent for the skeptic to maintain that I could be mistaken whether (a) or (b) is the case, since obviously if scenario (a) is the case, then I'm NOT mistaken. In other words, when the skeptic says "it's always possible that one is mistaken", it's not clear what he means by 'possible'. For if I do see (truly) that I have hands, then it is logically impossible for me to be in this very same state and be mistaken (that is, in the state of truly seeing that I have hands).
Well, we both presumably agree that what is the case is not the same thing as what could be the case. If I order a cup of coffee with no cream, there is a possibility that this cup of coffee will still have cream. What actually is the case is distinct from what is possibly the case.
To put it another way, then, I think possibility is a way of expressing indeterminacy and a lack of information. This is important in the field of statistics, but in the present case, the evil demon exists as a possibility because we do not have enough information to show that direct perception is actually the case. Possibility, in this situation, is basically identical to hypotheses.
Now, I grant the assumption that (a) and (b) are subjectivity indistinguishable mental states, but the crucial point is that they are DIFFERENT kinds of mental states nonetheless. The former is a state of seeing truly how things are in the world, while the latter isn't.
But why do you want to "know for sure"? How is that any better than to "know".
We are fallible beings, and we should be open to criticism of our theories. To "know for sure" serves no purpose than to deny criticism, thus preventing error correction.
"Radically mistaken" may be extreme language, but we "know for sure" we labour under certain misapprehensions.
The fact that we are mistaken about the external world (and the internal world) does not render our knowledge useless or completely without truth.
Theories do not require support. They stand on their own merit.
Have you considered epistemological solipsism as a solution to the problem of asertaining certainty in the above cases presented by you?
concerning your question, I'm not sure what you mean by "epistemological solipsism", could you elaborate?
So, let me elaborate at the chance of sounding nonsensical. Doubt can only exist when there is lack of certainty. Solipsism is a certain belief. Therefore if one can doubt then solipsism is not an actuality, therefore your hands are real if you can doubt whether they are real...
Does that make sense?
Anyway, it seems to me like a weird strategy to affirm solipsism in order to refute skepticism, since the solipsist goes even further than the skeptic. And furthermore, solipsism is equally questionable as realism according to the skeptic, since you can't know neither the truth of solipsism nor realism.
Well, not quite. Because since the world and the self are the same thing in solipsism, then there can be no room for doubting the world since the self must exist.
Quoting Fafner
Well, the mere fact that you can doubt, presupposes that solipsism isn't the case, therefore they are real.
Hope I'm getting through...
It seems to me that even if this inference is correct, it still would not refute skepticism because the skeptic need not argue for strict solipsism (in your sense) for his argument to be disastrous for knowledge. A world in which only I exits and the evil demon deceiving me into believing that there's an external world is just as bad as a strictly solipsistic world, but since it is not solipsistic in your sense, your argument is incapable of disproving its possibility. (because surely, in the Evil Demon world you CAN sensibly entertain (and hence doubt) both the hypothesis that the external world is real, and the possibility that you are being deceived by the demon.)
Doesn't it only, more modestly, presuppose that you don't know that solipsism is the case?
Yes; but, I cannot doubt the fact that I am doubting. Therefore, if we take the evil demon path of assuming that everything can be doubted and nothing can be certain, then there's no room for doubt in the process of doubting itself. Hence, solipsism is false because you are doubting and are not certain, and doubt presupposes certainty. Thus, you doubting whether your hands are real means that you aren't living in a solipsistic world.
The point is that epistemologically, you wouldn't even be able to entertain that thought in a solipsistic world, where everything is certain and there's no room for doubt.
Are you certain of that? Or is that just your way of defining solipsism?
Yes, I'm quite certain that you cannot doubt in a solipsistic world since you are only aware of what you can know and there is no room for not knowing (doubt) since that is something beyond your known world.
Once again, the skeptic can restrict the scope of his skeptical claim and exclude the possibility of doubting one's doubt. The most interesting type of skepticism targets only the beliefs the could be doubted, but he is happy to exclude from his skepticism beliefs that logically cannot be doubted (such as the existence of the self, and perhaps some other things). But as it happens, the vast majority of our beliefs are such that they sensibly can be doubted, and thus if the skeptic is right then we are still in a serious epistemic trouble after all.
But, that's cheating. For that removes any chance of certainty, but since knowledge is possible, then that excludes the possibility of that assertion.
And of course the evil demon is merely an hypothesis, the skeptic doesn't actually claim to be able to prove that there is an evil demon (if this is what you meant).
If we inhabit a dream, for example, then there's no room for doubt because all your beliefs originate from yourself. I don't think that makes sense. What I'm getting at is that doubt can only exist if there is a lack in knowledge. In a dream everything is perfectly clear, there's no room for/to doubt the existence of the dream world itself because there is no room for doubt itself.
It's not logically impossible that I am the only being that exists but do not know it.
I think it's perfectly possible to ask yourself from within your own dream whether you are dreaming or not. Some people can in fact do just that (lucid dreamers).
Not had you eternally been in a dream, and had no sense of doubt due to everything in the world being the same as your level of knowledge about it.
But I don't see why does it have to be so.
And as I said before, even if we grant that you are correct, don't you agree that if an evil demon is causing your sensations (from outside your consciousness), you would then be able to doubt the evil demon world? (or imagine the scenario where the world has been completely destroyed 5 minutes ago, and only your brain is kept alive by the evil demon without you noticing anything. Surely in THIS world you can doubt both possibilities.)
I am pretty sure I have experienced doubt when dreaming.
Descartes purpose in the application of the Demon was to prove with consummate genius that only thought exists. If the evil demon can fool me into thinking that everything I am thinking is a delusion it follows that I can prove nothing to exist as all existence may be a deception.
Upon this basis Descartes establishes the premise of absolute doubt. This premise is too often relied upon by the amateur philosopher who can then dismiss any assertion pertaining to 'existent reality' upon the basis of the deceiving demon, or the premise that reality is believed to be real in dreams and therefore we have little call or proof to assert that it is more real when we are awake. The dream analogy and that of the demon are Descartes' fait accompli, for any assertion that reality might be firmly established beyond doubt.
However in his second meditation Descartes applies the notion of universal doubt, to bring us to an incontrovertible truth of the existence of 'something'.
Unfortunately a difficulty arises when Descartes expands that something to include something else.
The something that Descartes successfully proves in his second meditation is the existence of thought.
" But [suppose] there is a deceiver of supreme power and cunning who is deliberately and constantly deceiving me. In that case too I undoubtedly exist, if he is deceiving me; and let him deceive me as much as he can, he will never bring it about that I am nothing so long as I think that I am something. So after considering everything very thoroughly, I must finally conclude that this proposition, I am, I exist, is necessarily true whenever it is put forward by me or conceived in my mind."
There must be thought if indeed a demon is to pervert that thought. Thought cannot be perverted into believing that it (thought) does not exist.
This much, as the proof pertains to thought is incontrovertible, however Descartes applies a strict association of thought with an I thinking. At this juncture Cartesian philosophy begins to weaken. All that has effectively been proven is the existence of thought, yet the Demon might well be deceiving this " I" into believing that there is an " I" thing who does the thinking or even generates the thought independently. Because thought exists the existence of an I thinking does not necessarily follow.
Nietzsche addresses this fallacy quite beautifully and quite thoroughly in aphorism 17:
"So far as the superstitions of the logicians are concerned, I will never tire of emphasizing over and over again a small brief fact which these superstitious types are unhappy to concede - namely, that a thought comes when "it" wants to and not when "I" wish, so that it's a falsification of the facts to say that the subject "I" is the condition of the predicate "think." It thinks: but that this "it" is precisely that old, celebrated "I" is, to put it mildly, only an assumption, an assertion, in no way an "immediate certainty." After all, we've already done too much with this "it thinks": this "it" already contains an interpretation of the event and is not part of the process itself. Following grammatical habits we conclude here as follows: "Thinking is an activity. To every activity belongs someone who does the action, therefore -." With something close to this same pattern, the older atomists, in addition to the "force" which created effects, also looked for that clump of matter where the force was located, out of which it worked - the atom. Stronger heads finally learned how to cope without this "remnant of earth," and perhaps one day people, including even the logicians, will also grow accustomed to cope without that little "it" (to which the honourable old "I" has reduced itself)."
As such we are left with thought, nothing more and nothing less. The question then follows what is to be done with this thing... thought.
M
Except that the mineness or ownedness of thought is unquestionable. Thoughts always belong to someone; they do not float around freely.
Except that the mineness or ownedness of thought is unquestionable. Thoughts always belong to someone; they do not float around freely.
Thats interesting Janus, how did you arrive at this conclusion/assumption?
Did you read aphorism 17?
Not a Nietzsche fan I take it?
Please expand
M
Aphorism 17 is agreeable enough, and contradicts nothing I have said. How are thoughts known to us? By experience just like everything else, no? Have you ever experienced a thought that wasn't your own? (Note, I'm not taking about origins here).
Aphorism 17 questions the presumptive basis of the "I" You state that this is agreeable enough and yet you ask me to assume an "I" in order to answer the question.
If you are asking me if I believe that my thought belongs to me, I can only reply that I have no evidence to prove that it does and might best assume that it does not. It may tell me that I am an " I" .....but it also tells me lots of other things that are equally dubious.
All this 'putative "I" can assert, is that thought exists, it offers the tempting indulgence of a "me" and it appears to this 'me'.... to be having a good time doing so, possibly at the expense of the I or the me rather than to the benefit or even the proof of it.
If deterministic principles are true then this I is a foregone conclusion, all that it does is act out a material existence that was established at the point eruption of the big bang. As such I find the "I" to be a rather boring and somewhat predictable material entity.
It is the thought that is interesting from a thoughtful perspective, the material 'I' is destined to feed the maggots, however the thought on the other hand appears to originate from something potentially interesting.. it might even endure after the maggots.
M
As I see it, if (1)(b) is logically possible, then (*) is coherent. That it seems to the subject that he's in state (a) (and (b) seems impossible to him) doesn't imply that he's in state (a). Which leaves (b) as a logical possibility.
A different response is to reject (1)(b) as logically possible. That seems consistent with ordinary usage where the meaning of "hands" is defined by that use. And so the only alternative to (1)(a) is ordinary deception or error rather than systemic deception or error (e.g., it's logically possible that the subject's real hands have been amputated and he presents fake hands). So for the skeptic's argument to work, a speculative meaning (or use) of "hands" is required.
(Of course, knowledge could still be challenged on the basis of ordinary deception and error, but that's a separate argument.)
1) If seeming to see my hand were sufficient evidence for knowing that I see my hand, I would be able to distinguish the following two cases merely on the basis of seeming to see my hand:
a) My seeming to see my hand being the result of my actually seeing my hand.
b) My seeming to see my hand being the result of an evil demon playing with my mind.
2) Merely on the basis of seeming to see my hand, I cannot distinguish case (a) from case (b).
Therefore, seeming to seem my hand is not sufficient evidence for knowing that I see my hand.
That seems to get around the problem you are presenting the skeptic, since it is no longer being expressed in terms of two allegedly inconsistent premises. Instead it is expressed as one conditional premise, together with the claim that the consequent of that conditional is false.
Notice that I don't wish to deny the possibility to be in state (1b), of course that is a logical possibility. What I do deny is the possibility that one could be in the very same mental state as in (1a) and be deceived.
The skeptic of course doesn't claim to know whether I'm in state (1a) or (1b), but he claims that even if I'm lucky and I'm in fact in state (1a), the possibility of a mistake still exists, which I cannot rule out. But my point is that if one is in fact in state (1a) then there's no possibility of him to have the same experience and be mistaken.
And so you've proved that thought alone exists. To whom?
I agree that it's not possible to see your hands and be mistaken. But that is not what the skeptic is saying. The skeptic is saying that even if you do see your hands the possibility of being mistaken remains. The skeptic's claim is coherent if possibility is understood as a function of the information available to the subject rather than in an absolute (God's eye view) sense.
We've long since moved on from Descartes obsession with certainty - but he changed the terms of the philosophical debate: prior to him the big distinction in metaphysics was between form and content, after him it was all about mind and matter.
And so you've proved that thought alone exists. To whom?
To itself alone.
M
What do you mean "falilibility" of all processes? How do they fail? Is it our senses that fail us, or our interpretation of what they represent? When you say, "all processes" do you also mean processes like fusion and the evolving process of organisms by natural selection? Did natural selection fail in some way? By whose standards?
Quoting MetaphysicsNowWhy would one want to get around facts if one is trying to get at knowledge? We have instinctive knowledge and we have learned knowledge. Which one are you talking about?
Quoting MetaphysicsNow
Well, that's the thing. There is no distinction. Dualism is false. Mind and matter interact so they are made of the same substance. Whether you want to call that substance "non-physical/mental", or "physical/matter", does it really matter? No, it doesn't. Descartes went through all that trouble for nothing.
Makes sense to me.