By playing a crucial role in settling open issues in the philosophical debate about logical consequence, logical evidence has become the holy grail of inquirers investigating the domain of logic. However, despite its indispensable role in this endeavor, logical evidence has retained an aura of mystery. Indeed, there seems to be a great disharmony in conceiving the correct nature and scope of logical evidence among philosophers. In this paper, I examine four widespread conceptions of logical evidence to argue that all (...) should be reconsidered. First, I argue that logical apriorists are more tolerant of logical evidence than empiricists. Second, I argue that evidence for logic should not be read out of natural language. Third, I argue that if logical intuitions are to count as logical evidence, then their evidential content must not be propositional. Finally, I argue that the empiricist proposal of treating experts' judgments as evidence suffers from the same problems as the rationalist conception. (shrink)

David Hull's (1988c) model of science as a selection process suffers from a two-fold inability: (a) to ascertain when a lineage of theories has been established; i.e., when theories are descendants of older theories or are novelties, and what counts as a distinct lineage; and (b) to specify what the scientific analogue is of genotype and phenotype. This paper seeks to clarify these issues and to propose an abstract model of theories analogous to particulate genetic structure, in order to reconstruct (...) relationships of descent and identity. (shrink)

Andy believes that p because his tarot cards indicate that p. Betty believes that ∼p because her crystal ball reveals that ∼p. If Andy and Betty know that they disagree, and disagree because they engage in different practices, is Andy's belief that p rational? The answer depends in part on whether Andy has good reasons to think that reading tarot cards is reliable about the topic while reading crystal balls is not. If a person has good reasons to believe that (...) practice P1 is reliable while a competing practice P2 is not, then it is not irrational to form beliefs by engaging in P1. What if a person does not have good reasons to think that one practice is reliable about a topic while competing practices are not, though? In such cases, would Andy's awareness of the existence of competing practices, on its own, be enough to render his belief that p irrational? (shrink)

Because of the problems associated with ecological concepts, generalizations, and proposed general theories, applied ecology may require a new "logic" of explanation characterized neither by the traditional accounts of confirmation nor by the logic of discovery. Building on the works of Grunbaum, Kuhn, and Wittgenstein, we use detailed descriptions from research on conserving the Northern Spotted Owl, a case typical of problem solving in applied ecology, to (1) characterize the method of case studies; (2) survey its strengths; (3) summarize and (...) respond to its shortcomings; and (4) investigate and defend its underlying "logic". (shrink)

I argue that we need not accept Quine's holistic conception of mathematics and empirical science. Specifically, I argue that we should reject Quine's holism for two reasons. One, his argument for this position fails to appreciate that the revision of the mathematics employed in scientific theories is often related to an expansion of the possibilities of describing the empirical world, and that this reveals that mathematics serves as a kind of rational framework for empirical theorizing. Two, this holistic conception does (...) not clearly demarcate pure mathematics from applied mathematics. In arguing against Quine, I present a formal account of applied mathematics in which the mathematics employed in an empirical theory plays a role that is analogous to the epistemological role Kant assigned synthetic a priori propositions. According to this account, it is possible to insulate pure mathematics from empirical falsification, and there is a sense in which applied mathematics can also be labeled as a priori. (shrink)

I present and defend a unified, non-reductive analysis of the a priori and a posteriori. It is a mistake to remove all epistemic conditions from the analysis of the a priori (as, for example, Alvin Goldman has recently suggested doing). We can keep epistemic conditions (like unrevisability) in the analysis as long as we insist that a priori and a posteriori justification admit of degrees. I recommend making the degree to which a belief’s justification is a priori or a posteriori (...) solely dependent on the revisability relations that obtain among the faculties that deliver the belief and all other faculties. (shrink)