John Broome

Rationality requires various things of you. For example, it requires you not to have contradictory beliefs, and to intend what you believe is a necessary means to an end that you intend. Suppose rationality requires you to F. Does this fact constitute a reason for you to F? Does it even follow from this fact that you have a reason to F? I examine these questions and reach a sceptical conclusion about them. I can find no satisfactory argument to show that either has the answer ‘yes’. I consider the idea that rationality is normative for instrumental reasons, because it helps you to achieve some of the things you ought to achieve. I also consider the idea that rationality consists in responding correctly to reasons. I reject both.

Esteemed philosopher John Broome avoids the familiar ideological stances on climate change policy and examines the issue through an invigorating new lens. As he considers the moral dimensions of climate change, he reasons clearly through what universal standards of goodness and justice require of us, both as citizens and as governments. His conclusions—some as demanding as they are logical—will challenge and enlighten. Eco-conscious readers may be surprised to hear they have a duty to offset all their carbon emissions, while policy makers will grapple with Broome’s analysis of what if anything is owed to future generations. From the science of greenhouse gases to the intricate logic of cap and trade, Broome reveals how the principles that underlie everyday decision making also provide simple and effective ideas for confronting climate change. Climate Matters is an essential contribution to one of the paramount issues of our time.

Reasoning is a process through which premise-attitudes give rise to a conclusion-attitude. When you reason actively you operate on the propositions that are the contents of your premise-attitudes, following a rule, to derive a new proposition that is the content of your conclusion-attitude. It may seem that, when you follow a rule, you must, at least implicitly, have the normative belief that you ought to comply with the rule, which guides you to comply. But I argue that to follow a rule is to manifest a particular sort of disposition, which can be interpreted as an intention. An intention is itself a guiding disposition. It can guide you to comply with a rule, and no normative belief is required

Two options are incommensurate in value if neither is better than the other, and if a small improvement or worsening of one does not necessarily make it determinately better or worse than the other. If a person faces a sequence of choices between incommensurate options, she may end up with a worse options than she could have had, even though none of her choices are irrational. Yet it seems that rationality should save her from this bad outcome. This is the practical problem posed by incommensurability of values, and it may be solved by a new account of practical reasoning.

Intuition suggests there is no value in adding people to the population if it brings no benefits to people already living: creating people is morally neutral in itself. This paper examines the difficulties of incorporating this intuition into a coherent theory of the value of population. It takes three existing theories within welfare economics - average utilitarianism, relativist utilitarianism, and critical-level utilitarianism - and considers whether they can satisfactorily accommodate the intuition that creating people is neutral.