Hume was no nihilist. He thought that we construct a satisfactory ethics from our sympathies and our ability to put ourselves in the place of others. For Parfit this is not good enough. Hume provides no reliable way of appealing against someone who is convinced that pain is intrinsically good or that there is nothing wrong with torturing babies. But pain is bad and torturing babies is wrong. Parfit thinks that normative properties like goodness and right must exist outside of our minds. But they are not identical to anything in the natural world. Normative properties, he argues, are like mathematical properties. They are similarly accessible to reason and have no causal impact on worldly events.

Some of the philosophers in Singer’s collection agree that ethical properties exist outside our minds but have doubts about Parfit’s account of their nature. Larry Temkin thinks that their influence on our behaviour shows that they have causal power. Frank Jackson is convinced that ethical properties are reducible to properties in the natural world in much the same way as heat is reducible to the motion of molecules. Mark Schroeder favours a ‘conservative’ reduction to natural properties that does not conflict with our intuitive knowledge of ethical truth.

Peter Singer, in his own contribution to the collection (with co-author Katarzyna de Lazari-Radek), welcomes Parfit’s objectivism because it confirms his long-held view that reason is the only reliable guide to right and wrong. Impartial rationality, he believes, tells us that we should sacrifice much more of our wealth to help those in need and the fact that most of us do not feel that we have this duty is no justification for refusing.

Many of the contributing philosophers side with Hume. Some do so because they think that an ethics detached from motivations is implausible. Moral judgements, according to Stephen Darwall, make agents accountable for what they do. But it is incoherent to hold people accountable unless they are capable of having moral motivations. Michael Smith argues that subjectivists have means of explaining why some normative statements cannot reasonably be denied. Sharon Street thinks that Parfit’s objectivism fails to explain how humans as products of evolution can recognise ethical truth. Simon Blackburn believes that ethics as a practice must engage our motivations, and he thinks that Parfit’s position is defective because he does not explain how this happens. Blackburn thinks that subjectivists are entitled to rely on their ethical beliefs and to regard them as true when they are the products of reflection and can withstand criticism.

How can there be ethical truth when people with different subjectivities are apt to disagree about right and wrong? The threat of ethical relativism makes Parfit’s objectivism appealing, but it leaves him with the problem of explaining why philosophers disagree, not only about particular issues, but also about the moral theory that ought to guide our actions. Parfit’s strategy is to argue that these theories, properly interpreted, are not really at odds with each other. Coming from different directions, they converge on the view that right action is in accordance with principles which, if they were universally accepted, would make things go best. The problem with this strategy is that it risks misrepresenting philosophers’ views. Andrew Huddleston convincingly argues that Parfit does not succeed in making Nietzsche’s anti-egalitarianism compatible with the ethical consensus that he wants to achieve. Ethical disagreement remains a problem for Parfit, as well as for subjectivists.

Peter SingerThere is one matter on which all the contributors to the collection agree: that some things matter, and thus that Parfit’s life was not wasted. Temkin thinks that Parfit’s claim that only his objectivism can save us from nihilism is implausible. Even if ethics is invented, it matters what we invent. Street says that things matter because we believe they do. Those who stop caring need more sleep, a healthier diet, or medication.

What these philosophers are implying is that meta-ethics doesn’t matter very much – except to those specialists who are interested in the problems that it raises. They imply that the rest of us can ignore theories about where ethical beliefs come from and get on with living our lives, just as we can happily live our lives without a thought about quantum physics. Parfit did not waste his life, but if these philosophers are right, and if his primary concern was to determine how we ought to live, then he wasted a lot of precious time writing a three-volume work on meta-ethics.

Do On What Matters and the essays in this collection matter? We are creatures naturally disposed to find meaning in our activities. But when we take a step away from human preoccupations and put ourselves and our activities under what Spinoza called the perspective of eternity, it is reasonable to wonder whether our values and lives have any significance whatsoever. Parfit, following in the footsteps of Plato and other great philosophers, did not think that this fundamental question could be avoided. I agree.