Descartes's "Demon"

Metaphysics and Epistemology
1

Hello all,

I’m new to the forums, and relatively new to objectivism and philosophy as a whole (about a year of serious thinking.)

 

The question I have is related to the infamous Cartesian demon. Descartes argues that it is impossible to truly know that the world around is is not some sort of illusion, perpetrated by some malicious demon or another.

Moving beyond the mysticism of the demon, is there any way that one *can* be completely confident that the world is as we conceive it? Is it not possible that, even as our senses perceive something, there is an error of some sort or another in our conception that prevents us from correctly interpreting these senses? 

 

Thank you for your time.  

 

Zigs

2

Doesn’t the question itself assume that you exist, that you are asking a question, that you have reason enough to evaluate answers and so on? 

Welcome to the forum.

3

Welcome to the forum.

2 hours ago, TheZigs said:

Is it not possible that, even as our senses perceive something, there is an error of some sort or another in our conception that prevents us from correctly interpreting these senses?

I can add in here: in order for something to be possible, there has to be some evidence for it. In the absence of any evidence, it can be dismissed as arbitrary.

1 Like
4

 

8 hours ago, TheZigs said:

Is it not possible that, even as our senses perceive something, there is an error of some sort or another in our conception that prevents us from correctly interpreting these senses?

In a sense, yes; that is always possible.

 

In that same sense, it’s impossible to ever *know* for certain that unicorns don’t tapdance on Jupiter. Since you cannot prove a negative (in the sense of “prove” that most philosophers use) you can neither disprove the existence of Jovan unicorns nor of Descartes’ demon.

 

Furthermore, in proving positives, it is always possible that we don’t have all the necessary information to arrive at the truth. So we can never *know* anything as an absolute; beyond the possibility of doubt or revision (which is what “knowing” meant to Descartes).

 

8 hours ago, TheZigs said:

Moving beyond the mysticism of the demon, is there any way that one *can* be completely confident that the world is as we conceive it?

Yes. 

 

One of Ayn Rand’s greatest insights (in my own words) was that knowledge is for action. To say that “X is true” doesn’t mean that “I will never have to reexamine or revise X ever again”; it means “I have enough evidence to assume and act on X, for now”.

 

So while it’s technically “possible” that we’re all in the Matrix right now, in a limited sense, in the abscence of any evidence it shouldn’t factor into anybody’s decisions about anything; we can basically assume that it’s false (which is what DW was referring to, about the arbitrary).

 

In essence, the problem with Descartes’ Demon is that it drops the context of what knowledge is and what it’s meant for.

 

 

8 hours ago, TheZigs said:

Thank you for your time.

It’s my pleasure.  :thumbsup:

 

Welcome to the forum.

 

P.S.

 

If you’re interested in further research, the Ayn Rand Lexicon is an excellent place to start.

Arbitrary

Proof

Objectivity

5

Harrison said:

 

Quote

Furthermore, in proving positives, it is always possible that we don’t have all the necessary information to arrive at the truth. So we can never *know* anything as an absolute; beyond the possibility of doubt or revision (which is what “knowing” meant to Descartes).

 

It’s important point out that this is not an Objectivist tenet.

The statement itself is a claim to know absolutely that we cannot know anything absolutely.

Edit: also it is an assertion of an arbitrary “possible”. There is no evidence that we are in a matrix, therefore the evidentiary category of “possible” does not apply.

1 Like
6

20 hours ago, Plasmatic said:

It’s important point out that this is not an Objectivist tenet.

I had meant for it to be.

 

20 hours ago, Plasmatic said:

Edit: also it is an assertion of an arbitrary “possible”. There is no evidence that we are in a matrix, therefore the evidentiary category of “possible” does not apply.

Strictly speaking, yes. However, I was trying to use “possible” in the sense Descartes used it (that it wouldn’t necessarily contradict anything else I know). That’s not the sense in which Peikoff used it, which is why I put it in scare quotes and stressed the different ways in which I was using those words.

I was trying to convey the same ideas through more conventional language; language which is ultimately wrong, but more accessible to beginners. I thought I’d succeeded in leaving the underlying message intact.

 

20 hours ago, Plasmatic said:

The statement itself is a claim to know absolutely that we cannot know anything absolutely.

A stolen concept! I actually laughed out loud, when I saw it.

 

I look forward to reading a more accurate response.  :thumbsup:

7

David Kelley’s “The Evidence of the Senses”, originally his PhD dissertation and since reworked into a book available at Amazon, is the complete examination of the philosophical issues involving the senses.   I long ago made a thread to give a taste of what is in it at Notes on “The Evidence of the Senses”.  

In the last chapter Kelley puts forward three principles of justified perceptual judgement and treats the case of when one can make a justified error of perceptual judgement, that a Not-F is F.  Such a possibility does not undermine confidence in the senses in general, because this conclusion is itself the product of knowledge gained through perception.  A general skepticism is self-refuting as logical conclusion and so can only be held as an arbitrary a priori premise.  Since an arbitrary a priori premise follows from no evidence, it can be dismissed without evidence. 

8

Thank you all for your responses. 

 

I have read both what you have said on the topic and what Peikoff wrote in OPAR, and understand the Objectivist position on the arbitrary claim that Descartes makes. It is now more clear to me *why* I have no reason to believe this demon is possible at all, or to act on its conclusion. 

 

Zigs