Responses to Skepticism

By Michael Gakuran | | Philosophy | Leave a comment |

skepticismHere I consider a couple of other responses to skepticism interesting in their own right. Both Externalist and Internalist responses also try to refute skepticism too.

The thing to note when thinking about contextualism is, in a way, it’s going outside the box to try and deal with skepticism. Recall the Closure argument for skepticism:

(P1) I do not know that I am not a brain in a vat (BIV).
(P2) I know that ‘I have hands’ entails I am not a BIV.
(P3) If I know something p, and I believe q by correctly deducing it from my belief that p, then I know that q. (Closure Argument)
(C) Thus, I do not know that I have hands, because I do not know that I am not a BIV.

It seems we only have 3 responses to the skeptic (paraphrased from The Stanford Encyclopedia of Philosophy):

1) We accept skepticism and admit we may not have hands.
2) We deny the Closure principle and thus refute the skeptic’s argument.
3) We reply in the style of G.E. Moore by twisting the Closure argument around on the skeptic (see Closure)

The contextualist says we have another option. We can argue that the skeptical view doesn’t really threaten our common sense views…

    Epistemic Contextualism

Why not consider that certain terms we use are dependent on the context we use them in? We certainly understand this notion in everyday life. When we say that a man is bald, do we just mean that he has absolutely no hairs on his head? No hairs on his whole body? What about one hair? Or 100 hairs spread apart but very small and almost unnoticeable?

The idea is that our standards for what is baldness or heaviness (etc.) are dependent on the subject matter. Heavy for a human or heavy for a forklift truck? Flat for a country (Holland) or flat for a bowls green? Even on the bowls green there would be tiny bumps…

We could distinguish these standards in terms of ‘high’ and ‘low’. When we speak of low standards, we mean situations like those above, where we want to distinguish comparatively heavy objects from light ones. But what about higher standards? Things that are *really* heavy? What about things that we know? And things that we *really* know?

The epistemic contextualist will want us to consider this. ‘Knows’ is similar to ‘heavy’ or ‘bald’. In ordinary contexts, we just use the word ‘knows’ to determine knowledge in low standards. For example, whether I heard something from a reliable source or not. But what about in skeptical contexts? Under the notion that I’m being deceived by an Evil Demon or am actually a brain in a vat being sent electronic signals by a computer, can we say we know? Maybe not, because it is in a skeptical context.


So what’s this about standards? Contextualists say that standards are dependent on the attributor, that is, the person who utters the word ‘know’ (this may be different from the subject). Consider the two bank cases (from my lecture notes by Daniel Elstein):

“Case 1

On Friday, Susan intends to go to the bank on the way home to pay in a cheque. But when she drives past the bank, before she parks her car, she spots that there is a long queue. Susan says to her housemate who is in the car with her, ‘I know that the bank will be open tomorrow, because I remember that it opens on Saturdays, so I can go tomorrow.

Case 2

The same set-up, except that now Susan needs to pay in the cheque before Monday, in order to avoid going overdrawn when her next bill goes out. This time Susan says, ‘I remember the bank opening on Saturdays, but perhaps they have changed their hours, and I can’t afford to go overdrawn. Since I don’t know that the bank will be open tomorrow, I should get out and check.’”

In case 2, Susan is less inclined to say she ‘knows’. She has the same evidence in both cases, but but contextualists say that the epistemic standards are higher in case 2. If she doesn’t pay the cheque in before Monday, she will go overdrawn. The stakes are higher, and consequently the epistemic standards are too.

Similarly, in the brain in a vat case, the epistemic standards of knowing are higher. When asked normally ‘do you know that you exist?’, the intuitive answer is ‘yes’. But in the context of Epistemology when philosophising I am asked the same question, the appropriate answer is ‘no’, because there are higher standards. The problem arose because we amalgamated two different contexts.

In terms of our Closure argument, we can keep hold of it with contextualism. In ordinary ‘low standards’ contexts, the claim ‘I know I have hands’ is true, but in ‘high standards’ contexts, it is false. So contextualists hold that we can protect our ordinary knowledge claims.

But hold on here, why do epistemic standards rise in skeptical contexts?

A few considerations:


Cohen’s view is that the level of justification required changes. This is an internalist view governed by a rule of salience (relevance). Mentioning skeptical situations increases the salience which, in turn, requires us to increase the amount of justification we need to say we know something. But this seems strange as then it seems like I have justification to know I’m not a brain in a vat, but as soon as I mention that I raise the standards and can no longer say it. Furthermore, it doesn’t seem like we have any justification for believing we aren’t brains in vats…

Rule of Sensitivity

Another answer might be DeRose’s externalist ‘Rule of Sensitivity‘. When asked if I know something, the standards rise to require sensitivity to that something as to whether or not it is true. This focuses on truth-tracking by sensitivity. I must be able to track the truth by my reasons or evidence for certain propositions. For example, Just by saying ‘I know that I’m not a BIV’, sensitivity to the statement is required. But I can’t be sensitive to such a statement because it’s impossible for me to know (I have no evidence), so I don’t know that I’m not a BIV. So it’s false to say I have hands by Closure. But in ordinary contexts, with no mention of BIVs, it’s true to say ‘I know I have hands’ because I can be sensitive to whether or not I have hands (I see them in front of me).

Rule of Attention

Lewis’s is a Relevant Alternatives account of contextualism. Knowing something ‘p’, we have to rule out relevant alternatives to p – the ones Lewis says are not ‘properly ignored’. Given any situation, certain ‘not p’ alternatives will be ‘properly ignored’ – they will not be relevant to us. Whether or not and alternative is ‘properly ignored’ will depend on the context.

As such, Lewis argues that in epistemology we starting attending to alternatives that we wouldn’t usually attend to, so they become relevant alternatives to us (they are no longer ‘properly ignored’). When asking whether or not we are BIVs, we must thereby attend to that possibility, and our evidence cannot eliminate it.

It’s a curious view as it basically says that, if we’re not paying attention to it, it doesn’t count as an alternative. Before I started considering whether or not I was a BIV, I knew I had hands, but after considering it, I no longer know. In other words, by doing epistemology, we start to lose knowledge!!

I knew Philosophy was nuts. …But do I really know that Philosophy is nuts if I can’t be sure I’m not a brain in a vat..? oo…er…


But hang on, once we move into our higher standards skeptical context and we find we can’t know we have hands, shouldn’t we be saying we never actually knew we had hands? The claim ‘I know that I have hands seems to be true only because it wasn’t really about knowledge. In ordinary contexts, ‘I know I have hands’ is not true because I veridically know I have hands, it’s only true because the word ‘know’ has a different meaning. In the higher skeptical contexts, we take ‘know’ at its highest meaning. Hence normal people in ordinary contexts don’t veridically (really, truly) know they have hands after all. They just speak the truth when they say ‘I know I have hands’ because of the context in which they use the word ‘know’.

One more point to consider is the relevance of skeptical hypotheses. Like above where I said, could I ‘know’ whether or not Philosophy is nuts if I don’t know I’m not a brain in a vat, there seems to be a certain intuition to ignore the skeptical idea. It just seems irrelevant to consider it. As with the example my lecturer Daniel Elstein gave, do I know global warming is taking place if I don’t now I’m not a brain in a vat? I could just be being deceived into thinking global warming is taking place! It seems completely irrelevant to my knowing about global warming and taking the necessary steps to help stop it whether or not I’m a brain in a vat! But by thinking this way, we are denying the intuitive Closure argument that we base normal knowledge on…

Maybe worrying about BIVs is epistemically relevant, but it certainly doesn’t seem relevant to my addressing the problem of global warming…

    Semantic externalism

Firstly, let’s get the skeptical argument clear (from The Stanford Encyclopedia of Philosophy):

“In a famous discussion, Hilary Putnam has us consider a special version of the brain-in-a-vat hypothesis. Imagine that you are a brain in a vat in a world in which the only objects are brains, a vat, and a laboratory containing supercomputers that stimulate the envatted brains. Imagine further that this situation has arisen completely randomly, and that the brains have always been envatted. No evil neuroscientists or renegade machines have brought about the brains’ envatment. Call such a special brain in a vat a ‘BIV’. A skeptical argument just like that above can be formulated using the BIV hypothesis. Putting things now in the first person, Putnam argues that I can establish that I am not a BIV by appeal to semantic considerations alone — considerations concerning reference and truth. This will block the BIV version of the skeptical argument.”

I’ve unfortunately run out of time to ponder over this argument and give it adequate consideration here, but the article Brains in a Vat on the Stanford Encyclopedia of Philosophy is very interesting. Go and read it for Putnam’s argument to try and show we aren’t brains in a vat!


Sources: Lecture handouts written by my lecturer Daniel Elstein, The Internet Encyclopedia of Philosophy and The Stanford Encyclopedia of Philosophy

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