Underdetermination and Perceptual Skepticism

This chapter motivates narrowing the book’s focus to a particular kind of argument for perceptual skepticism (the underdetermination argument) and to two main kinds of response to it (inferential anti-skepticism and noninferential anti-skepticism). The first half of the chapter sets aside skeptical arguments (e.g. closure-based arguments) and responses to them (e.g. contextualism, contrastivism, and closure-denial) that overestimate skepticism’s appeal by taking for granted that we don’t know that skeptical hypotheses are false. It also sets aside disjunctivist and “knowledge first” responses to skepticism, both of which underestimate skepticism’s appeal by rejecting the intuitions supporting the New Evil Demon Problem. The second half of the chapter highlights the relative strength of underdetermination arguments for perceptual skepticism, according to which our sensory evidence underdetermines the truth of our perceptual beliefs based on it. This underdetermination problem requires us to be able to infer the likely truth of our perceptual beliefs via good arguments from our sensory evidence, if our perceptual beliefs are to be justified. Given that we aren’t able to make such inferences, the underdetermination argument concludes that our perceptual beliefs aren’t justified. The inferential anti-skeptic’s response insists that we are able to make such inferences. The noninferential anti-skeptic’s response says that, despite the underdetermination problem, our perceptual beliefs can be justified even if we aren’t able to infer their likely truth via good arguments from our sensory evidence.

Global and Memory Skepticism

This chapter begins by briefly considering some direct arguments for global skepticism (according to which none of our beliefs are justified) and finding them unacceptable. It then outlines a piecemeal (underdetermination-based) case for global skepticism, which argues that underdetermination problems afflict not only perception but also memory, a priori intuition, introspection, and reasoning, thereby undermining the justification for all of our beliefs. It also explains what’s wrong with self-undermining objections (e.g. Susanna Rinard’s), according to which the conclusion of arguments for global skepticism (i.e. that none of our beliefs are justified) undermines the rationality of belief in the premises of such arguments, thereby neutering their skeptical force. Finally, it lays out an underdetermination argument for memory skepticism and explains why anti-skeptical arguments from our memory evidence to the likely truth of the memory beliefs based on that evidence are unsuccessful. Although a discussion of the underdetermination problems for a priori intuition, introspection, and reasoning is required to complete the presentation of the piecemeal argument for global skepticism, that discussion is postponed until the following chapter.

4. Realism and anti‐realism

‘Realism and anti-realism’ is concerned with the debate between scientific realism and its converse, anti-realism or instrumentalism. Realists hold that the aim of science is to provide a true description of the world. Anti-realists hold that it is to provide a true description of the ‘observable’ part of the world. The ‘no miracles’ argument, one of the strongest arguments for scientific realism, is shown to be a plausibility argument — an inference to the best explanation. Central to the debate between realism and anti-realism is the observable/unobservable distinction and the views of realist Grover Maxwell and anti-realist Bas van Fraassen are described. The underdetermination argument is also explained.

The Defect in Effective Skeptical Scenarios

What epistemic defect needs to show up in a skeptical scenario if it is to effectively target some belief? According to the false belief account, the targeted belief must be false in the skeptical scenario. According to the competing ignorance account, the targeted belief must fall short of being knowledge in the skeptical scenario. This paper argues for two claims. The first is that, contrary to what is often assumed, the ignorance account is superior to the false belief account. The second is that the ignorance account ultimately hobbles the skeptic. It does so for two reasons. First, when this account is joined with either a closure-based skeptical argument or a skeptical underdetermination argument, the best the skeptic can do is show that we don’t know that we know. And second, the ignorance account directly implies the maligned KK principle.

Uses of Value Judgments in Science: A General Argument, with Lessons from a Case Study of Feminist Research on Divorce

The underdetermination argument establishes that scientists may use political values to guide inquiry, without providing criteria for distinguishing legitimate from illegitimate guidance. This paper supplies such criteria. Analysis of the confused arguments against value-laden science reveals the fundamental criterion of illegitimate guidance: when value judgments operate to drive inquiry to a predetermined conclusion. A case study of feminist research on divorce reveals numerous legitimate ways that values can guide science without violating this standard.