We present an argument about the methodology of ethics, broadly conceived, drawing on recent research on modelling in the philosophy of science. More specifically, we argue that normative ethics should adopt the methodology of modelling. We make our case in two parts. First, despite the perhaps unfamiliar terminology, modelling already happens in ethics. We identify it, and argue that its practice could be improved by recognising that it is modelling and by adopting some methodological lessons from philosophy of science. Second, modelling should be adopted more widely within normative ethics, because it fits well with various methodological ends we shall identify. Models can be used to investigate ethical questions in a manner that is systematic but relatively free of foundational theoretical commitments in first-order ethics. Models are more local, and less ambitious, than theories. They can be used to break deadlocks, by focusing attention on the particularities of a sub-domain and by providing a common tool–the surrogate model system–which each side can use to make their principles precise, illustrate the implications of their view, and identify sources of disagreement or points of agreement. We are pluralists about method, so this is not a call to abandon other philosophical methods. It is simply a plea for modelling, motivated by the method’s independent benefits and its fruitfulness in resolving some persistent methodological problems in ethics.

The Procreation Asymmetry, in strongest form, states (roughly) that while we have no reason to create happy people, we do have reason not to create unhappy people. Despite its popularity among non-utilitarian philosophers, it has been surprisingly difficult to give an adequate theoretical defense of this asymmetry. However, in a recent paper, Johann Frick attempts to provide a unified account of the asymmetry that avoids the problems with previous attempts. One of Frick’s novel claims is that a certain wide-scope conditional reasons principle, together with two plausible inference rules, serves to capture both conjuncts of the asymmetry. We argue that while Frick’s account is more plausible than previous accounts, it can explain the asymmetry only by appealing to a unexplained further asymmetry that in effect reaffirms the asymmetry, and that the wide-scope conditional reasons principle does not help to provide a satisfactory explanation of the asymmetry.

This chapter argues that collectivist duties do not significantly affect our individual obligations in certain important coordination problems. These are moral high stake versions of the so-called Hi-Lo cases. This also means that the conflict between collectivists and individualists, who resist the collectivist move, is not that stark in these cases. Along the way, I will also show that Hi-Lo cases are of interest to all kinds of moral theories, not just consequentialism, for which it is usually seen as a challenge.

The fact that our attitudes change poses well-known challenges for attitude-sensitive wellbeing theories. Suppose that in the past you favoured your adventurous youthful life more than the quiet and unassuming life you expected to live as an old person; now when you look back you favour your current life more than your youthful past life. Which period of your life is better for you? More generally, how can we find a stable attitude-sensitive standard of wellbeing, if the standard is in part defined in terms of unstable attitudes? In this paper, I introduce an 'attitudinal matrix' framework that will help us clear up the problems posed by changing attitudes across time. In particular, it will help us see what is at stake, which principles that can or cannot be combined, and what might be the best solution. I defend a very plausible candidate constraint on a solution to the challenge of changing attitudes, which I call 'diagonalism'. It is argued that among the three main forms of substantive attitude-sensitive wellbeing theories - the attitude-version, the object-version, and the satisfaction-version - it is the satisfaction-version that can both satisfy diagonalism and provide the best account of temporal and lifetime wellbeing.

Among health economists, who think that preferences are the correct standard of the value of health states, it is common to assume, at least implicitly, that the correct criterion of this value takes the following schematic form: H1 is a better health state than H2 iff the members of group S prefer (on average) being in H1 to being in H2. Various candidates for members of S have been proposed, including medical experts, the general public, H1-patients, H2-patients, former H1-patients, former H2-patients, or combinations of these groups. I shall argue that criteria of this form run into serious problems, if we consider cases where people’s fundamental preferences change from one health state to another. I shall also show that these problems afflict hybrid views, according to which preferences are only one determinant of the value of health, the objective value of health states being another. Finally, I shall argue that a better subjectivist criterion would be something like this: H1 is a better health state than H2 iff the H1-patients would want to be in H1 more than the H2-patients would want to be in H2. According to this criterion, the value of a health state is determined by the absolute attitudes (favouring, disfavouring, neutrality) people would have towards a health state were they to be in it. Along the way, I will also present and make use of an attitude matrix framework that enables us to represent in a simple way complex information about attitudes. With this framework at hand, we can easily see the advantages and disadvantages of different subjectivist accounts of the value of health.

Just as we can be more or less certain that there is extraterrestrial life or that Goldbach’s conjecture is correct, we can be more or less certain about normative matters, such as whether euthanasia is permissible or whether utilitarianism is true. However, accommodating the phenomenon of degrees of normative certitude is a difficult challenge for non-cognitivist and expressivist views, according to which normative judgements are desire-like attitudes rather than beliefs (Smith, in: Evaluation, Uncertainty, and Motivation. Ethical Theory and Moral Practice 5: 305–320, 2002). Several attempts have been made on behalf of non-cognitivism and expressivism to meet the challenge (Lenman in: Non-cognitivism and the dimensions of evaluative judgment, Brown Electronic Article Review Service, 2003; Ridge in Synthese 2003. https://doi.org/10.1007/s11229-018-1884-7; Ridge in: Shafer-Landau (ed) Studies in metaethics, Oxford University Press, Oxford, 2007; Sepielli in Philos Stud 160: 191–207, 2012; Eriksson and Francén Olinder in Aust J Philos 94: 719–735, 2016). These attempts have all been found wanting (Bykvist and Olson in Philos Q 59:202–215, 2009, Aust J Philos 95:794–799, 2017; Bykvist and Olson 2012). Michael Ridge has recently offered a quasi-realist solution, according to which expressivists can say exactly what cognitivists say about certitude, including normative certitude. In this paper, we explain the basic problem and Ridge’s quasi-realist solution. We then argue that the quasi-realist account of normative certitude faces severe difficulties that do not arise for cognitivist accounts, according to which normative judgements are beliefs.

Recently, there has been a revival in taking empirical magnitudes seriously. Weights, heights, velocities and the like have been accepted as abstract entities in their own right rather than just equivalence classes of objects. The aim of my paper is to show that this revival should include value magnitudes. If we posit such magnitudes, important value comparisons (cross-world, cross-time, mind to world, cross-theory, cross-polarity, ratio) can be easily explained; it becomes easier to satisfy the axioms for measurement of value; goodness, badness, and neutrality can be given univocal definitions; value aggregation can be given a non-mathematical understanding which allows for Moorean organic unities. Of course, this does not come for free. One has to accept a rich ontology of abstract value magnitudes, but, to quote David Lewis, 'The price is right; the benefits in theoretical unity and economy are well worth the entities.'

Broome’s target in his paper is the popular claim that rationality consists in responding correctly to reasons. He takes this to be the reductive claim that rationality reduces to responding correctly to reasons, which in turn he takes to entail that the property of rationality is identical to the property of responding correctly to reasons. It is this identity claim that Broome attempts to refute by showing that the properties that are supposed to be identical cannot be so because they themselves do not share all properties. In this short commentary, I shall say something about the overall structure of Broome’s argument. More specifically, I shall argue that in its current form his argument rests on a very controversial premise, but that it can be replaced with an argument that avoids it and has wider significance. I shall also question the way Broome deals with the so-called Kantian argument against his own argument. Finally, I shall sketch an alternative view of rationality, which agrees with Broome that it supervenes on the mind, but disagrees with him on the question of whether it itself is a purely mental property.