Online research in philosophy

Derek Parfit’s mere addition paradox has generated a large literature. This paper articulates one response to this paradox - which Parfit hirnself suggested - in terms of a formal account of the relation of parity. I term this response the ‘parity view’. It is consistent with transitivity of ‘at least as good as’, but implies incompleteness of this relation. The parity view is compatible with critical-band utilitarianism if this is adjusted to allow for vagueness. John Broome argues against accounts which involve incompleteness. He thinks they are based on an intuition of ‘neutrality’, which is most naturally understood in terms of equality. There is no rationale, on Broome’s view, for seeing it as ‘incommensurateness’ which leads to incompleteness. Parity provides one. Broome’s worries that ‘incommensurateness’ makes neutrality implausibly ‘greedy’, and that ‘incommensurateness’ and vagueness are incompatible do not constitute a knock-down case against the parity view. Similar worries arise for his preferred vagueness view.

Responses to John Broome and John Brunero.

The Interpersonal Addition Theorem, due to John Broome, states that, given certain seemingly innocuous assumptions, the overall utility of an uncertain prospect can be represented as the sum of its individual (expected) utilities. Given ‘Bernoulli's hypothesis’ according to which individual utility coincides with individual welfare, this result appears to be incompatible with the Priority View. On that view, due to Derek Parfit, the benefits to the worse off should count for more, in the overall evaluation, than the comparable benefits to the better off. Pace Broome, the paper argues that prioritarians should meet this challenge not by denying Bernoulli's hypothesis, but by rejecting one of the basic assumptions behind the addition theorem: that a prospect is better overall if it is better for everyone. This conclusion follows if one interprets the priority weights that are imposed by prioritarians as relevant only to moral, but not to prudential, evaluations of prospects.

When we have a normative reason, and we act for that reason, it becomes our motivating reason. But we can have either kind of reason without having the other. Thus, if I jump into the canal, my motivating reason was provided by my belief; but I had no normative reason to jump. I merely thought I did. And, if I failed to notice that the canal was frozen, I had a reason not to jump that, because it was unknown to me, did not motivate me. Though we can have normative reasons without being motivated, and vice versa, such reasons are closely related to our motivation. There are, however, very different views about what this relation is. This disagreement raises wider questions about what normative reasons are, and about which reasons there are. After sketching some of these views, I shall discuss some arguments by Williams, and then say where, in my opinion, the truth lies. [...] I [will] suggest why, as I believe, we should be non-reductive normative realists, and should regard all reasons as external.

This paper sketches a right-maker account of normative practical reasons along functionalist lines. The approach is contrasted with other similar accounts, in particular John Broome's analysis of reasons as explanations of oughts.

In “Weighing Lives” (2004) John Broome criticizes a view common to many population axiologists. On that view, population increases with extra people leading decent lives are axiologically neutral: they make the world neither better nor worse, ceteris paribus. Broome argues that this intuition, however, attractive, cannot be sustained, for several independent reasons. I respond to his criticisms and suggest that the neutrality intuition, if correctly interpreted, can after all be defended.On the version I defend,the world with added extra people at wellbeing levels within the neutrality range is incommensurable in value with the world in which these peaople are absent.

Some philosophers think that rationality consists in responding correctly to reasons, or alternatively in responding correctly to beliefs about reasons. This paper considers various possible interpretations of ‘responding correctly to reasons’ and of ‘responding correctly to beliefs about reasons’, and concludes that rationality consists in neither, under any interpretation. It recognizes that, under some interpretations, rationality does entail responding correctly to beliefs about reasons. That is: necessarily, if you are rational you respond correctly to your beliefs about reasons.

In the last decade, it has become commonplace among people who work on reasons (although not uncontroversially so) to distinguish between normativity and rationality. Work by John Broome, Niko Kolodny, Derek Parfit, and Nicholas Shackel has helped to establish the view that rationality is conceptually distinct from reasons. The distinction allows us to make sense of the questions recently addressed by Broome, Kolodny, Reisner, and Shackel: is rationality normative, and if so, in what way? Kolodny’s ‘Why be Rational?’ answered the first of these questions by claiming that there is no reason to be rational. In order to argue for this conclusion, Kolodny argues for a process account of rationality. Kolodny’s view is that rational requirements govern mental processes. His view is set in direct contrast to Broome’s, who holds that rational requirements are primarily, and perhaps exclusively, concerned with relations among mental states at a time.