This thesis is an investigation into the nature of epistemic justification. It brings together themes from traditional, individual-centred epistemology, and collective, group-centred epistemology. The first half of the thesis is concerned with the question of whether rationality is epistemically permissive; that is, whether one body of evidence can rationalise more than one doxastic attitude. In chapter 1, I argue that permissive cases are best understood as epistemic standard conflicts. Doing so provides us with a novel understanding of the arbitrariness objection (...) against permissivism and enables us to reduce questions about epistemic permissibility to questions about the nature of incommensurability. In chapter 2, I show that the defended understanding of permissive cases generalises by defending it against an objection from self-fulfilling beliefs. In chapter 3, I demonstrate that we can use this view of epistemic rationality to generate so-called divergence arguments which show that the epistemic status of group-level attitudes and member-level attitudes can rationally diverge. In the second half of the thesis, I develop a novel evidentialist theory of epistemic justification, called Continuous Evidentialism. Continuous Evidentialism is inspired by some general methodological reflections (chapter 4), which suggest that we should opt for a theory of epistemic justification that analyses the epistemic status of group-level attitudes and member-level attitudes continuously. According to Continuous Evidentialism, to have a justified belief is to possess sufficient evidence and utilise that evidence in an epistemically responsible way when forming the belief. While I argue that we can reduce epistemic responsibility to higher-order evidentialist requirements. In chapter 5, I develop a theory of evidence, evidence possession and epistemic basing. Chapters 6 - 8, discuss various complications of the proposed theory, having to do with the alleged defeasibility of justification (chapter 6), epistemic responsibility (chapter 7), and the proposed reduction of epistemic responsibility (chapter 8). In chapter 9, I compare Continuous Evidentialism to various extant accounts. (shrink)

Jesper Kallestrup has provided an insightful response to our paper, “Epistemic Structure in Non-Summative Social Knowledge”. Kallestrup identifies some important issues pertaining to our non-summative, non-supervenient account of group knowledge which we did not address in our original paper. Here, we develop our view further in light of Kallestrup’s helpful reply.

Deflationism about group knowledge is the view that a group has knowledge if and only if most of its members have that knowledge. The case against deflationism has revolved around epistemic divergence arguments, which typically aim to show that members’ knowledge isn’t necessary for group knowledge. This paper is instead devoted to objections against members’ knowledge being sufficient for group knowledge. Focusing on structured groups in which members occupy roles that are connected by internal links in a social network, we (...) develop a notion of knowledge qua such occupancy. We proceed to argue that if deflationists adopt such knowledge-qua as what constitutes structured group knowledge, they have the resources to counter worries about the sufficiency condition. If instead groups are taken to be feature collectives, then similar worries are much less pressing. Finally, we elaborate on the societal function of knowledge-qua, as well as the different epistemic assessments that arise, depending on whether the role or its occupant is considered. (shrink)