David Chalmers supports his contention that there is a possible world populated by our zombie twins by arguing for the assumption that conceivability entails possibility. But, I argue, the modal epistemology he sets forth, ‘modal rationalism,’ ignores the problem of incompleteness and relies on an idealized notion of conceivability. As a consequence, this epistemology can’t justify our quotidian judgments of possibility, let alone those judgments that concern the mind/body connection. Working from the analogy that the imagination is to the possible (...) as perception is to the actual, I set forth a competing epistemology, ‘modal empiricism.’ This epistemology survives the incompleteness objection and allows some of our everyday modal judgments to be justified. But this epistemology can’t justify the claim that Zombie World is possible, which leaves Chalmers’s property dualism without the support it needs. (shrink)

A longstanding philosophical premise perceives simplicity as a desirable attribute of scientific theories. One of several raised justifications for this notion is that simple theories are more likely to indicate the true makeup of natural systems. Qualitatively parsimonious hypotheses and theories keep to a minimum the number of different postulated entities within a system. Formulation of such ontologically simple working hypotheses proved to be useful in the experimental probing of narrowly defined bio systems. It is less certain, however, whether qualitatively (...) parsimonious theories are effective indicators of the true nature of complex biological systems. This paper assesses the success of ontologically simple theories in envisaging the makeup of three complex systems in bacteriology, immunology, and molecular biology. Evidence shows that parsimonious theories completely misconstrued the actual ontologically complex constitutions of the three examined systems. Since evolution and selective pressures typically produce ontologically intricate rather than simple bio systems, qualitatively parsimonious theories are mostly inapt indicators of the true nature of complex biological systems. (shrink)

The “Evidentialist Dictum” says we must believe what our evidence supports, and the “Fallibility Norm” says we must take our fallibility into account when managing our beliefs. This paper presents a problem for the Evidentialist Dictum based in the Fallibility Norm and a particular conception of evidential support. It then addresses two novel Evidentialist responses to this problem. The first response solves the problem by claiming that fallibility information causes “evidence-loss.” In addition to solving the problem, this response appears to (...) explain what’s wrong with certain illegitimate dismissals of misleading evidence. However, this explanation opens it up to objections. Next, I consider and pose challenges to an Evidentialist strategy that attempts to solve the problem by converting accounts of fallibility’s epistemic significance for rational belief into principles of evidential support. I conclude by sketching a solution that allows us to capture what’s true in the Evidentialist Dictum and the Fallibility Norm. (shrink)