Epistemologists who study credences have a well-developed account of how you should change them when you learn new evidence; that is, when your body of evidence grows. What's more, they boast a diverse range of epistemic and pragmatic arguments that support that account. But they do not have a satisfactory account of when and how you should change your credences when you become aware of possibilities and propositions you have not entertained before; that is, when your awareness grows. In this (...) paper, I consider the arguments for the credal epistemologist's account of how to respond to evidence, and I ask whether they can help us generate an account of how to respond to awareness growth. The results are surprising: the arguments that all support the same norms for responding to evidence growth support a number of different norms when they are applied to awareness growth. Some of these norms seem too weak, others too strong. I ask what we should conclude from this, and argue that our credal response to awareness growth is considerably less rigorously constrained than our credal response to new evidence. (shrink)

Many have offered accounts of the procreative asymmetry, the claim that one has no moral reason to create a life just because it would be happy, but one has moral reason not to create a life just because it would be miserable. I suggest a new approach. Instead of looking at the procreative asymmetry on its own, we can situate it within a broader landscape of asymmetries. Specifically, there are two other analogous asymmetries in the prudential and epistemic domains. The (...) prudential asymmetry says that one has no prudential reason to acquire a desire just because it would be satisfied, but one has prudential reason not to acquire a desire just because it would be frustrated. The epistemic asymmetry says that one has no epistemic reason to acquire a belief just because it is true, but one has epistemic reason not to acquire a belief just because it is false. The existence of these analogous asymmetries in these normative domains suggests the possibility of a unified account of all three asymmetries as instances of a more fundamental asymmetry of value-based reasons. This paper develops a working model of what such a unified account might look like. Such an account can give us a unified explanation of a variety of phenomena, reinforce the plausibility of each of these asymmetries, and give us a novel picture of how value gives us reasons that might extend beyond these three applications. (shrink)

In response to two trenchant objections, radical subjective Bayesianism has been widely rejected. In this paper, I seek, if not to rehabilitate subjectivism, at least to show its critic what is attractive about the position. I argue that what is at stake in the subjectivism/anti-subjectivism debate is not, as is commonly thought, which norms of rationality are true, but rather, the conception of rationality that we adopt: there is an alternative approach to the widespread telic approach to rationality, which I (...) call the poric approach, on which subjectivism is an attractive position. I then argue that the poric approach—and therefore subjectivism—cannot be easily dismissed. (shrink)

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)

Catastrophic risk raises questions that are not only of practical importance, but also of great philosophical interest, such as how to define catastrophe and what distinguishes catastrophic outcomes from non-catastrophic ones. Catastrophic risk also raises questions about how to rationally respond to such risks. How to rationally respond arguably partly depends on the severity of the uncertainty, for instance, whether quantitative probabilistic information is available, or whether only comparative likelihood information is available, or neither type of information. Finally, catastrophic risk (...) raises important ethical questions about what to do when catastrophe avoidance conflicts with equity promotion. (shrink)

Katie Steele and H. Orri Stefánsson argue that, to reflect an agent’s limited awareness, the algebra of propositions on which that agent’s credences are defined should be relativised to their awareness state. I argue that this produces insurmountable difficulties. But the project of relativising the agent’s algebra to reflect their partial perspective need not be abandoned: the algebra can be relativised, not to the agent’s awareness state, but to what we might call their subjective modality.

There are many reasons we might want to take the opinions of various individuals and pool them to give the opinions of the group they constitute. If all the individuals in the group have probabilistic opinions about the same propositions, there is a host of pooling functions we might deploy, such as linear or geometric pooling. However, there are also cases where different members of the group assign probabilities to different sets of propositions, which might overlap a lot, a little, (...) or not at all. There are far fewer proposals for how to proceed in these cases, and those there are have undesirable features. I begin by considering four proposals and arguing that they don't work. Then I'll describe my own proposal, which is intended to cover the situation in which we want to pool the individual opinions in order to ascribe an opinion to the group considered as an agent in its own right. (shrink)

This paper aims to open a dialogue between philosophers working in decision theory and operations researchers and engineers working on decision-making under deep uncertainty. Specifically, we assess the recommendation to follow a norm of robust satisficing when making decisions under deep uncertainty in the context of decision analyses that rely on the tools of Robust Decision-Making developed by Robert Lempert and colleagues at RAND. We discuss two challenges for robust satisficing: whether the norm might derive its plausibility from an implicit (...) appeal to probabilistic representations of uncertainty of the kind that deep uncertainty is supposed to preclude; and whether there is adequate justification for adopting a satisficing norm, as opposed to an optimizing norm that is sensitive to considerations of robustness. We discuss decision-theoretic and voting-theoretic motivations for robust satisficing, and use these motivations to select among candidate formulations of the robust satisficing norm. (shrink)

In the present paper, we consider the implications of our work on the logical priority of the epistemic, the thesis that persons’ options are determined in the first instance by their relevant knowledge and ignorance, for the legitimacy of claims that some decision-maker bears an unconditional obligation to make a particular decision or perform a specific action (i.e., categorical obligation attributions). We argue that the logical priority of the epistemic implies that many such attributions are misplaced, if not erroneous. We (...) defend Naturalistic Moral Error Theory, a novel theory which, though it bears many of the same consequences for moral discourse, is distinct in its metaphysical implications from J. L. Mackie’s (1977) famous moral error theory. (shrink)

Laurie Paul argues that, when it comes to many of your most significant life-changing decisions, the principles of rational choice are silent. That is because, in these cases, you anticipate that one of your choice options would yield a transformative experience. We argue that such decisions are best seen as ones in which you anticipate awareness growth. You do not merely lack knowledge about which possible outcome will arise from a transformative option; you lack knowledge about what are the possible (...) outcomes. We show how principles of rational choice can be extended to cases of anticipated awareness growth. (shrink)

My dissertation is about Bayesian rationality for non-ideal agents. I show how to derive subjective probabilities from preferences using much weaker rationality assumptions than other standard representation theorems. I argue that non-ideal agents might be uncertain about how they will update on new information and consider two consequences of this uncertainty: such agents should sometimes reject free information and make choices which, taken together, yield sure loss. The upshot is that Bayesian rationality for non-ideal agents makes very different normative demands (...) than ideal Bayesian rationality. (shrink)