The Refutation of Skepticism by Jonathan Vogel
What are some skeptical hypotheses that challenge our belief in the external world? Can they be refuted? Here’s what Vogel had to say.
Introduction to Skepticism
Skepticism is a philosophical position as per which our ability to have knowledge about the external world, reliability of our senses, etc. is challenged on the ground of lack of sufficient evidence to support them.
Overview of Vogel’s Arguments
The Deceiver Argument
As per this argument, we might be victims of an extensive sensory deception. It can be understood with the help of the following scenario:
Situation 1: Everything is normal. I am sitting on my desk and writing this blog.
Situation 2: I am the subject of an experiment. My brain is inside a laboratory vat. Made-up, illusionary data is being fed to it. It appears to me that I am sitting on my desk and writing this blog, even though I am not.
I have no way of knowing which of these situations I am in. Therefore, I don’t really know if I am sitting on my desk and writing this blog.
To generalize, because we do not know if we are suffering from sensory deception or not, we do not know anything about the world at all.
The Underdetermination Principle
As per the underdetermination principle, if ‘a’ is a competitor to ‘b’, then one can know ‘b’ only if one can reject ‘a’ non-arbitrarily. Or, in the case that ‘a’ is a competitor to ‘b’, then one can know ‘b’ only if ‘b’ has more epistemic merit than ‘a’.
Take a normal case in which we do not have knowledge. I see that the clock in my living room has stopped working. It could be that its cell had run out. Or it could be that there is a problem in its internal mechanisms due to which it is no longer working. These are two explanations. If I have no further information regarding the matter, I would have no rational basis for favoring one explanation over the other, as one would not have more epistemic merit than the other. My choice of accepting any of the two hypothesis would therefore be arbitrary or underdetermined.
Refuting the Deceiver Argument
The deceiver argument can be presented formally in the following argument format:
Premise 1: Take proposition m about the world (m being a mundane proposition). For me to know that m, my belief that m must not be underdetermined.
Premise 2: My belief that m is underdetermined
Conclusion: Therefore, I do not know that m.
The underdetermination principle has been applied in the first premise, as it shows that we fail to know that m if there is another competing proposition of equal epistemic merit (Underdetermination harms a thing’s claim to be knowledge).
The second premise states that for each mundane proposition, there is another competing proposition with equal epistemic merit. This competing proposition is a skeptical hypothesis.
The conclusion that we get from these two premises is that skepticism about external world prevails because we can not know that m.
The structure of the argument given above is valid. It can only be refuted by a successful attack on at least one of its two premises. But the first premise (based on underdetermination principle) seems to be immune to any attack through logical reasoning. This leaves the second premise. To refute the deceiver argument, this second premise must be shown to be weak or false. This argument presents the domestic skeptic position.
It is important to note that the deceiver argument is dependent upon a number of epistemic principles, the underdetermination principle being one of them. Some other principles are those of sufficient reason, testimony, causation and coherence.
The Domestic Skeptic Position
The deceiver argument suggests that we lack the knowledge of world that we assume to have. Even though it does not bring into question the legitimacy of the epistemic principles commonly accepted, it can be seen as being dangerous insofar as it suggests that we have absolutely no knowledge about the external world, that too by employing the epistemic principles deemed acceptable by us. The domestic skeptic position can be refuted if the legitimacy of the epistemic principles is shown to be weak or is nullified.
On the Refutation of Skepticism
If one can prove that mundane propositions have more epistemic merit than their skeptical competitors (thus refuting the second premise), the case for skepticism as laid out by the deceiver argument would crumble.
Five Popular Positions
The following five positions are the popular ones prevailing amongst philosophers in the debate surrounding skepticism:
- Skepticism is at least ‘conditionally correct’ and is incapable of refutation
- Epistemic rationality compels us to reject the skeptical hypotheses
- Methodological conservatism (as per which we have the right to maintain beliefs we already have — including mundane propositions — given that everything else remains equal) requires that we reject the skeptical hypotheses
- Mundane propositions have, as their immediate justification — experience. This should be a reason to believe in them and reject the skeptical hypotheses (as the latter is not justified through experience)
- Mundane propositions can be accepted over skeptical hypotheses if they can be proved to not be dialectically/pragmatically self-refuting or logically inconsistent like the latter
Even though Vogel recognizes that these views hold some merit, he concludes that they are unjustified and thus inadmissible.
Vogel’s Alternate Position
Vogel puts forward his support for the theory of inference to the best explanation (IBE) as his own position. As per IBE, if I am to choose between competing beliefs 1 and 2, I would have a sufficient reason to accept 1 over 2 if the former has, in its support, a better explanation of the relevant situation.
As per IBE, mundane propositions are far better than their skeptical competitors at explaining any concerned body of facts, particularly (as is important here) facts pertaining to our mental lives. Thus, choosing the former over the latter would not be underdetermined and skepticism could be refuted by the refutation of the second premise of the deceiver argument.
While he acknowledges that IBE, as an approach, faces some notable obstacles (like the ambiguity of the classification of an explanation as being good), he takes explanatory goodness as a given and does not delve into addressing the criticisms raised against it.
Understanding Different Hypotheses
Minimal Skeptical Hypothesis
As per the MSH, our experience is simply delusionary. So, for every thing that we experience, there is something causing us to have that false experience (one can call this ‘something’ an evil demon/computer/mad scientist or whatever). Vogel holds that the explanatory power of MSH is weak. To elucidate his point, the explanation for MSH can be compared to a statement like “I am feeling hungry because something is causing me to feel hunger.”
Real World Hypothesis
The RWH aims to explain the aspects of the actual world that one lives in (like the different events and objects we experience in everyday life). These hypotheses use observations, evidence and reasoning as their basis. These have high explanatory merit. For example, the theory of gravity is a RWH from physics.
Isomorphic Skeptical Hypothesis
The ISH mirrors our real experiences, but introduces skeptical doubts that affect our ability to have justified knowledge about the external world. In other words, these hypotheses aim to show how the evidence we rely on can be explained from a skeptical perspective also. They have equally high explanatory merit which is similar to the RWH. For example, all our sensory experiences are a result of a highly advanced virtual reality simulation.
Grounds for rejecting skeptical hypotheses
- Skeptical hypotheses like MSH can be rejected on explanatory grounds
- Even structurally similar ISH cannot easily substitute RWH and assume equal explanatory merit as this would involve immense theory construction liable to failure
- RWH has explanatory advantages over the skeptical hypotheses
Empirical Knowledge Through Causal Relation as a Motivation for Skepticism
Causal relation has been accepted as being the main source of empirical knowledge. But causal relations are contingent and could have been caused by anything (you could go by the RWH, or you could go by the ISH/MSH).
But such an explanation would not seem as natural as that of the RWH — if X appears as X, it might be because X is X, and not because an ‘evil demon’ is causing a delusion and making it appear like it is X.
The RWH has IBE as its advantage while the ISH/MSH are disadvantaged by their lack of simplicity. But the former, too, has some convincing criticism against it, which will be explained below.
Criticisms Against IBE
- Epistemic justification would have no value unless the beliefs that have a higher degree of it also have a higher chance of being true. Believing in the IBE is assuming that a simple explanation is most likely to be the truth about a certain thing/situation. But this seems to be wishful thinking/sophistry — assuming that the world is as simple and tidy as can be. Thus, RWH (through IBE) may have an edge over skeptical hypotheses on the ground of pragmatic explanation, but this does not signify that they have greater epistemic justification in their favor too.
- The same types of criticisms that are raised against enumerative induction can be raised against IBE. It supports the acceptance of those hypotheses that are not entailed in the available evidence.
The Three Positions
Vogel puts forward three positions after assuming that knowledge requires justification. He says that if one is not of position 2, one can reject position 1. But if one is skeptic about IBE (position 2), one has reasons to adopt position 3 and 1, too.
- Skepticism about external world
- Skepticism about IBE
- Skepticism about Induction
Commentary
- Vogel claims that skepticism about IBE is exotic (as opposed to domestic; it brings into doubt the efficacy of the epistemic principles). This can extend to induction as well. Those of the opinion that there is no rational grounds for challenging epistemic principles might dismiss such skepticism as being exotic.
- The above mentioned position takes for granted the validity of the epistemic principles and thus may seem unsatisfactory. It is hard to deny that the criticisms against IBE/induction have some strength to them. Evidence could be misleading, no matter how strong it seems.
Fumerton’s Requirement
Philosopher Richard Fumerton put forward his concept of Fumerton’s Requirement, as per which a belief would only count as knowledge if it is based on other beliefs/evidence that give justification for it. In simpler words — if one wants to claim to have knowledge, one must be equipped with reasons supporting that belief.
FR can be applied to skepticism by saying that skeptics require strong justification to accept a belief as knowledge. So, skeptics could deny the belief in the existence of external world as it is based on perceptual evidence and claim that we lack the means to establish the existence of the external world without any doubt. This can be taken as a point in support for domestic inductive skepticism.
Thus, skeptics could use the FR to raise the standard of justification required for knowledge and thus point to the flaws in our acceptance of everyday beliefs.
Takeaway
Vogel attempts to show that there are some forms of skepticism that can be challenged and refuted, and explicates the ways in which one can do that. He emphasizes how these ways too have flaws and that there are types of skepticism that perhaps cannot be refuted.
