Aggregative moral theories face a series of devastating problems when we apply them in a physically realistic setting. According to current physics, our universe is likely _infinitely large_, and will contain infinitely many morally valuable events. But standard aggregative theories are ill-equipped to compare outcomes containing infinite total value so, applied in a realistic setting, they cannot compare any outcomes a real-world agent must ever choose between. This problem has been discussed extensively, and non-standard aggregative theories proposed to overcome it. (...) This paper addresses a further problem of similar severity. Physics tells us that, in our universe, how remotely in time an event occurs is _relative_. But our most promising aggregative theories, designed to compare outcomes containing infinitely many valuable events, are sensitive to how remote in time those events are. As I show, the evaluations of those theories are then relative too. But this is absurd; evaluations of outcomes must be absolute. So we must reject such theories. Is this objection fatal for all aggregative theories, at least in a relativistic universe like ours? I demonstrate here that, by further modifying these theories to fit with the physics, we can overcome it. (shrink)

This thesis is about the moral reasons we have to do less than best. It consists of six chapters. Part I of the thesis proposes, extends, and defends reasons to do less than best. In Chapter One (“The Conditional Obligation”) I outline and reject two recent arguments from Joe Horton and Theron Pummer for the claim that we have a conditional obligation to bring about the most good. In Chapter Two (“Agglomeration and Agent-Relative Costs”) I argue that agent-relative costs can (...) justify permissions to less than best in a far greater range of decisions contexts than we currently believe. In Chapter Three (“Risk and Aggregation”) I discuss how anti-aggregative moral theories deal with risk, whilst proposing an argument in favour of ex-post moral theories. -/- In Part II of the thesis, I discuss longtermism, presenting a series of reasons to believe we have both significant permissions and obligations to prioritise those in the short-term. In Chapter Four (“Listening to Future People”) I criticise a recent argument presented by Andreas Mogensen for the claim we cannot have obligations grounded in the wellbeing of future people. I then show that, even permitting the existence of obligations to future people, we still have significant reasons to resist longtermism on the grounds of partiality. In Chapter Five (“The Complaints of Future People”) I argue that scepticism about aggregation is inconsistent with an obligation, or indeed even a permission, to help far future people. In Chapter Six (“Leaving the Present Behind”) I explore the moral significance of “dooming”, whilst arguing that we have a pro tanto reason of fairness to prioritise aiding those currently in existence. (shrink)

Our universe is both chaotic and (most likely) infinite in space and time. But it is within this setting that we must make moral decisions. This presents problems. The first: due to our universe's chaotic nature, our actions often have long-lasting, unpredictable effects; and this means we typically cannot say which of two actions will turn out best in the long run. The second problem: due to the universe's infinite dimensions, and infinite population therein, we cannot compare outcomes by simply (...) adding up their total moral values - those totals will typically be infinite or undefined. Each of these problems poses a threat to aggregative moral theories. But, for each, we have solutions: a proposal from Greaves let us overcome the problem of chaos, and proposals from the infinite aggregation literature let us overcome the problem of infinite value. But a further problem emerges. If our universe is both chaotic and infinite, those solutions no longer work - outcomes that are infinite and differ by chaotic effects are incomparable, even by those proposals. In this paper, I show that we can overcome this further problem. But, to do so, we must accept some peculiar implications about how aggregation works. (shrink)

Suppose you found that the universe around you was infinite—that it extended infinitely far in space or in time and, as a result, contained infinitely many persons. How should this change your moral decision-making? Radically, it seems, according to some philosophers. According to various recent arguments, any moral theory that is ’minimally aggregative’ will deliver absurd judgements in practice if the universe is (even remotely likely to be) infinite. This seems like sound justification for abandoning any such theory. -/- My (...) goal in this thesis is simple: to demonstrate that we need not abandon minimally aggregative theories, even if we happen to live in an infinite universe. I develop and motivate an extension of such theories, which delivers plausible judgements in a range of realistic cases. I show that this extended theory can overcome key objections—both old and new—and that it succeeds where other proposals do not. With this proposal in hand, we can indeed retain minimally aggregative theories and continue to make moral decisions based on what will promote the good. (shrink)