The thesis investigates the implications for moral philosophy of research in psychology. In addition to an introduction and concluding remarks, the thesis consists of four chapters, each exploring various more specific challenges or inputs to moral philosophy from cognitive, social, personality, developmental, and evolutionary psychology. Chapter 1 explores and clarifies the issue of whether or not morality is innate. The chapter’s general conclusion is that evolution has equipped us with a basic suite of emotions that shape our moral judgments in (...) important ways. Chapter 2 presents and investigates the challenge presented to deontological ethics by Joshua Greene’s so-called dual process theory. The chapter partly agrees with his conclusion that the dual process view neutralizes some common criticisms against utilitarianism founded on deontological intuitions, but also points to avenues left to explore for deontologists. Chapter 3 focuses on Katarzyna de Lazari-Radek and Peter Singer’s suggestion that utilitarianism is less vulnerable to so-called evolutionary debunking than other moral theories. The chapter is by and large critical of their attempt. In the final chapter 4, attention is directed at the issue of whether or not social psychology has shown that people lack stable character traits, and hence that the virtue ethical view is premised on false or tenuous assumptions. Though this so-called situationist challenge at one time seemed like a serious threat to virtue ethics, the chapter argues for a moderate position, pointing to the fragility of much of the empirical research invoked to substantiate this challenge while also suggesting revisions to the virtue-ethical view as such. (shrink)

This paper presents arguments and evidence from psychology and neuroscience supporting Lipton’s 2004 claim that scientists create knowledge through an abductive process that he calls “Inference to the Best Explanation”. The paper develops two conclusions. Conclusion 1 is that without conscious effort on our part, our brains use a process very similar to abduction as a powerful way of interpreting sensory information. To support Conclusion 1, evidence from psychology and neuroscience is presented that suggests that what we humans perceive through (...) our senses is not reality, but rather, our ‘brain’s “best guess” of the causes of its sensory input. The implication of this best guessing is that our brains use a process very similar to abduction throughout our lives to inform us of what is happening in the world around us. In addition, an argument based on Darwinian evolution is presented claiming that our brains do an excellent job of interpreting sensory information from the outside world. (If they did not, we, as a species, could hardly have survived.) Combining these two claims leads to Conclusion 1. Building on Conclusion 1, Conclusion 2 is that Lipton and others are correct in claiming that scientists use abduction when creating scientific theories. Abduction must be strong, because Nature chose abduction for its own sensemaking purposes. This paper’s contribution to knowledge is in pointing out that recent psychological and neuroscientific research has major implications for the philosophical world’s confidence in the probable validity of abductive inference. The punchline is simple: Nature chose abduction! (shrink)

A key question in the philosophy of logic is how we have epistemic justification for claims about logical entailment (assuming we have such justification at all). Justification holism asserts that claims of logical entailment can only be justified in the context of an entire logical theory, e.g., classical, intuitionistic, paraconsistent, paracomplete etc. According to holism, claims of logical entailment cannot be atomistically justified as isolated statements, independently of theory choice. At present there is a developing interest in—and endorsement of—justification holism (...) due to the revival of an abductivist approach to the epistemology of logic. This paper presents an argument against holism by establishing a foundational entailment-sentence of deduction which is justified independently of theory choice and outside the context of a whole logical theory. (shrink)

While the epistemic significance of disagreement has been a popular topic in epistemology for at least a decade, little attention has been paid to logical disagreement. This monograph is meant as a remedy. The text starts with an extensive literature review of the epistemology of (peer) disagreement and sets the stage for an epistemological study of logical disagreement. The guiding thread for the rest of the work is then three distinct readings of the ambiguous term ‘logical disagreement’. Chapters 1 and (...) 2 focus on the Ad Hoc Reading according to which logical disagreements occur when two subjects take incompatible doxastic attitudes toward a specific proposition in or about logic. Chapter 2 presents a new counterexample to the widely discussed Uniqueness Thesis. Chapters 3 and 4 focus on the Theory Choice Reading of ‘logical disagreement’. According to this interpretation, logical disagreements occur at the level of entire logical theories rather than individual entailment-claims. Chapter 4 concerns a key question from the philosophy of logic, viz., how we have epistemic justification for claims about logical consequence. In Chapters 5 and 6 we turn to the Akrasia Reading. On this reading, logical disagreements occur when there is a mismatch between the deductive strength of one’s background logic and the logical theory one prefers (officially). Chapter 6 introduces logical akrasia by analogy to epistemic akrasia and presents a novel dilemma. Chapter 7 revisits the epistemology of peer disagreement and argues that the epistemic significance of central principles from the literature are at best deflated in the context of logical disagreement. The chapter also develops a simple formal model of deep disagreement in Default Logic, relating this to our general discussion of logical disagreement. The monograph ends in an epilogue with some reflections on the potential epistemic significance of convergence in logical theorizing. (shrink)