I wrote this paper as part of a group project in my philosophy class last semester. I'm entirely open to the fact that I (and the others in my group) am wrong regarding a lot of this stuff, considering none of us are actually philosophers, nor did we feel we learned enough in the course to believe we had learned anything at all. On a positive note, our professor did say we had one of the best papers (out of seven or eight haha), and we did get an A, so perhaps we did better than I thought. If you need clarification on anything, just ask. Oh, and we had to send this paper to a journal on the off chance that they would publish it... we chose Analysis.
Response to Goldman's Underdetermination Argument
Alan Goldman's essay, 'The underdetermination argument for brain-in-the-vat scepticism,' claims that we have evidential reason to prefer belief in our physical world to the brain-in-the-vat hypothesis (2007:32). He uses an analogy of a murder trial to support this claim. This paper attempts to refute his claim by arguing that a 'possible worlds' argument is not compatible with scepticism, and that his analogy does not account for human error and prejudice, nor does it prefer physical world hypotheses over all sceptical hypotheses.
Goldman describes Duncan Pritchard's allowance of externalist knowledge that we are not brains in vats. He states that this knowledge requires 'belief that remains true in most or nearly all nearby possible worlds' (2007:32). He continues this idea by 'assuming that if the world in which we are BiV is distant, the belief that we are not BiV remains true in nearby possible worlds' (Pritchard 2005: 75). The possible worlds argument is an explanation of simplicity. It is impossible to make this assumption in regards to scepticism. For there to be any nearby possible worlds, there must be a world of origin. Since scepticism doubts the existence of an original world, making the assumption that an original world exists is the same as making the assumption that sceptical doubts are false. This is similar to Moore's anti-sceptical argument:
'(1) If I don't know that I'm not a brain in a vat (BiV), then I don't know that I have hands (or that there's a tree in the garden, or a book on the table--or any other apparently evident everyday fact).
(2) I do know I have hands (and so on).
(3) So I know that I'm not a BiV' (Rudd 2008:306).
Moore's argument ignores the sceptical questions, and by doing so, comes to a conclusion that is contrary to sceptical doubt. Arguments like these require a true belief that the world is real in the first place, and scepticism calls into question the truth of this belief.
Goldman creates the analogy of a murder trial to support his claim against scepticism. The evidence is made up of several unbiased witnesses, each of whom claim to have seen the butler stab his employer several times after a quarrel. Later, the knife was found in the butler's quarters with his fingerprints and his employer's blood. The defense attorney claims the evidence is equally compatible with a scenario in which a look-alike committed the crime in order to frame the butler.
Goldman explains what most jurors would choose in the court case of the butler when he says.
'I assume that everyone in the jury, and indeed everyone in the nation save perhaps our tight circle of epistemologists, would agree that they can know on the basis of the evidence that the butler is guilty and should decide the case accordingly' (Goldman 33:2007).
The reason they would know on the basis of evidence that the butler is guilty is due to their biased opinion based on expectations of a common occurrence, in this instance spontaneous murder over a complicated murder plot. If they did not have this bias then they would consider the scenario in which the look-alike did it as equally probable as the scenario in which the butler committed the murder. With this equal probability the jurors would be incapable of finding the butler guilty based on reasonable doubt.
The scenario in which the butler did it is the anti-sceptical argument, and the scenario in which the look-alike did it is the sceptical argument. Goldman states that,
'In order to have this knowledge [that the butler is guilty], the jurors would not need to know the structure of inferences to the best explanation. Nor would they be required to specify those features of best explanations that make them better than alternatives. Nor would they need to justify the claim that inference to the best explanation tends to be truth preserving. Nor finally would they feel the need to explain the "appeal" of the alternative story, the sceptical argument in the case. The compatibility of all the evidence with the sceptical scenario would not make this explanation very appealing to them. What they would know is that the evidence clearly favours belief in the butler's guilt. Knowing this, they would know the alternative story to be false, and they would know this on the basis of the evidence presented to them. The evidence indeed favours the obvious explanation over the arcane one, although it is compatible with both. It renders the former, but not the latter, probable' (Goldman 2007:32).
While it may be true that it is possible to have this knowledge that the butler is guilty, does this mean that it is possible to have the knowledge that scepticism is false? In the case of a murder trial, all that is required to find a defendant guilty is belief of guilt beyond reasonable doubt. To refute scepticism, absolute certainty is required, rather than belief in probability. In Goldman's explanation above, the probable idea is considered to be the correct one. What makes something more probable? Goldman answers this question with comparative simplicity:
'Our usual explanations for our perceptual beliefs are better for the same reason as, if not for stronger reasons than, the butler explanation is better. The bare brain-in-the-vat possibility is not an explanation at all unless detailed causal mechanisms are described. It is easier for the defense attorney than for the sceptical philosopher to describe in detail the possible means involved in the sceptical scenarios. If the philosopher could describe such means, they would have to mimic exactly our ordinary physical causes, but with added elements such as the mysterious motives and the vast technical knowledge of the programmers, making the explanation more complex than our usual ones. Comparative simplicity thus favours both the butler and the physical world hypotheses, if the latter’s competitor is explanatory at all' (Goldman 2007:34)
As Goldman notes, the complexity of the Brain in a Vat hypothesis arises when explaining its details. This allows for the preference of physical world hypotheses over the sceptical hypothesis of Brain in a Vat. But how does the simplicity of physical world hypotheses compare to other sceptical hypotheses, for instance Descartes' dream argument? Descartes' dream argument merely suggests that what we experience is a dream. This argument is just as simple, if not simpler, than physical world hypotheses. In a physical world hypothesis, it must be explained how things come into being, a task that is quite complicated; however, the dream argument avoids the complexity of explaining the origin of objects. The only reason Descartes' dream argument would seem more complicated than a physical world hypothesis is because we are accustomed to believing that we are not dreaming while we are consciously awake. If it was commonly believed that what we experience is a dream, then it would seem more complicated to believe a physical world hypothesis. Because the dream argument is simpler than physical world hypotheses, simplicity does not rule out sceptical doubt but actually supports it.
We have discussed Alan Goldman's essay, 'The underdetermination argument for brain-in-the-vat scepticism'. We have refuted his claim that we have evidential reason to prefer belief in our physical world to the brain-in-the-vat hypothesis (2007:32). This is done by arguing that a 'possible worlds' argument is not compatible with scepticism, and that his analogy does not account for human error and prejudice, nor does it prefer physical world hypotheses over all sceptical hypotheses. Finlay we have shown that comparative simplicity supports some sceptical hypotheses over physical world hypotheses.
References
Goldman, Alan H. 2007. "The underdetermination argument for brain-in-the-vat scepticism." Analysis 67, no. 1: 32-36. Religion and Philosophy Collection, EBSCOhost (accessed December 10, 2009).
Rudd, Anthony. 2008. "NATURAL DOUBTS." Metaphilosophy 39, no. 3: 305-324. Religion and Philosophy Collection, EBSCOhost (accessed December 10, 2009).
Pritchard, D. 2005. Epistemic Luck. Oxford: Clarendon Press.
This paper may have some errors in it since I'm not sure if it's the final copy. Anyway, enjoy!
