Abstract

In this study I investigate routes through which empirical conditions required for activities of knowing come to be relevant to questions of justification, relevant, that is, to questions about what can be concluded from evidence gathered. Thus it investigates concretely the reasoning at several sites where conditions external to the knower's mind become important to internal questions of justification. ;In Chapter 2 I analyze the reasoning associated with the Weak Anthropic Principle ---"what we observe may be restricted by the conditions necessary for our presence as observers." I show that this reasoning is not a straightforward application of the principle of total evidence, as has been claimed by John Earman, and hence is not a trivial instance of familiar rules of reasoning, as is widely believed. I begin the task of analyzing the general notion of a selection effect, and show that Copernicus argued for a Weak Anthropic selection effect in his suggestion that the earth moves. ;Chapter 3 gives a general account of transcendental arguments by identifying a distinctive piece of logical form which all such arguments share. This analysis shows that transcendental arguments need not have a priori premises, that Weak Anthropic reasoning is transcendental reasoning, and that transcendental arguments can generate as well as defuse skepticism. ;In Chapter 4 I identify reasoning about selection effects with reasoning about failure of provisoes , and investigate the role of this masoning in common and uncommon practices of discounting evidence. In the common case of a selection effect the grounds for believing there is a selection effect in evidence are independent of the theory under test. Cases where this fails are found in revolutionary science: Copernicus's hypothesis, the Marxist notion of false consciousness, and Newton's first law. I argue that self-insulation from falsification is found in some of our best scientific theories, and thus cannot by itself serve to disqualify a theory from scientificity. Further, such cases of selection effect expose a possible view of scientific revolutions according to which we can understand how disputes become inadjudicable without assuming theory-ladenness of observation