The Significance of Philosophical Skepticism

William S. Larkin

I. Epistemological Goal:

A. General understanding of our knowledge of propositions in a certain domain—e.g., propositions about the external world.

1. Do not want a big laundry list of various specific ways of knowing about the external world, but rather an understanding of how we know about the external world on the basis of a very general way of knowing—e.g., on the basis of sense perception.

2. Do not want to know how we know particular propositions about the external world given that we know other propositions about the external world, but rather an understanding of how we can know anything at all about the external world.

3. Pointing out that we in fact do have knowledge of the external world on the basis of sense perception does not provide an adequate philosophical understanding. We want to know how it is possible to know anything at all about the external world given certain apparently undeniable features of sense perception.

B. We want a philosophical explanation of the possibility of something that is presupposed given an apparent excluder of that possibility.

1. Explanandum: Knowledge of external world on the basis of sense perception.

2. Apparent Excluder: Certain features of sense perception

a. In sense perception we are never directly aware of objects.

b. Sense perception is fallible.

II. Skepticism and the Goal of Epistemology

A. Skeptical Argument

1. Essentially an attempt to show how apparently undeniable features of sense perception exclude the possibility of sensory knowledge of the external world.

2. Features of sense perception essentially add up to the claim that perceptual beliefs are not certain.

3. To get from that to skepticism need a claim about the nature of knowledge—that knowledge requires certainty.

4. Argument:

P1: Perceptual beliefs are not certain.

P2: Knowledge requires certainty.

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C: So perceptual beliefs do not count as knowledge.

B. The epistemological goal just is to refute the skeptical argument.

1. The argument structure is fine.

2. So the epistemological goal is to reject one of the skeptic’s premises.

a. If we reject P1 of the skeptic’s argument, then we will have learned something significant about the nature of sense perception—one of our deeply intuitive beliefs about the nature of sense perception is mistaken.

b. If we reject P2 of the skeptic’s argument, then we will have learned something about the nature of knowledge or our concept of knowledge—that it does not require certainty.

C. Moreover, any positive attempt to deny the significance of skepticism must presuppose an understanding knowledge, which as we have seen, requires responding to skepticism. So any attempt to deny the significance of skepticism is bound to be self-defeating.