A volume on utilitarianism in the ‘Very Short Introductions’ series would seem to be very long overdue, but perhaps the delay has proved fortuitous, with this excellent little volume appearing at a time when the classical utilitarian legacy has been reinvigorated in ways that were scarcely imaginable only a few decades ago. Indeed, had it appeared even a decade ago, it would have been a very different book, given the recent changes in co-author Peter Singer's views. Thanks in considerable measure to his fruitful collaboration with co-author Katarzyna de Lazari-Radek, Singer, surely the world's best-known utilitarian, has moved ever closer to the classical utilitarian views favoured by Henry Sidgwick, with a cognitivist intuitionist metaethics and hedonist value theory. This Sidgwickian turn was on full display in their previous and very substantial book, The Point of View of the Universe: Sidgwick and Contemporary Ethics (2014), and although this change is somewhat more in the background in the present work, which is meant as a general introduction to all forms of utilitarianism, it nonetheless makes its presence felt at many points. One comes away from this work with the bracing feeling that Sidgwickian utilitarianism is not only alive, but thriving.

To be sure, the authors do show how wide the bandwidth of utilitarianism has been. In their historical account, they nicely highlight the importance of the ancient Chinese philosopher Mozi (490–403 bce), and note the contributions of such figures as Richard Cumberland (1631–1718), whose work On Natural Laws was judged by Sidgwick himself to have been in key respects the breakthrough work advancing utilitarianism. But of course, their emphasis is rightly on the big three – Jeremy Bentham, John Stuart Mill and Sidgwick – though with a bow to William Godwin, who was more influential than Bentham in the early 1790s. Their readings of these figures are sensitive, sympathetic and reflective of the latest historical research in the field. The trajectory of the founding era is clear: ‘Over that period, it [utilitarianism] lost some of its early reforming zeal, but retained significant influence in politics and economics while becoming firmly established as a rational, if still controversial, approach to ethics’ (p. 14). In other words, it moved from Bentham to Sidgwick.

Intriguingly, as the historical narrative moves forward, with careful accounts of the views of such twentieth-century utilitarians as John Harsanyi, J. J. C. Smart and R. M. Hare, the aim is less to demonstrate progress and more to bring out the lines of convergence. Thus,

Such a point is very Sidgwickian, suggestive of his belief that utilitarian principles somehow undergird and systematize common-sense morality. But unlike those who would gloss such a strategy in terms of something like Rawlsian reflective equilibrium, a balancing of our various considered convictions, de Lazari-Radek and Singer deploy the work of Joshua Greene to argue that ‘a moral theory should not be judged by whether it matches our intuitions, many of which will be automatic moral responses that are no longer relevant to the situations we face today’ (p. 40). Our Pleistocene gut responses, which evolved in small group hunter-gatherer situations, are, if Greene is correct, demonstrably short on higher-order cognition, and moreover are the proper object of debunking arguments to the effect that, given their evolutionary backstory, there is little reason to think they track truth.

This is a key manoeuvre, informing the de Lazari-Radek/Singer position at many points and marking a step beyond their Sidgwickian inheritance. Greene's research ‘clears away the obstacles that have hindered acceptance of consequentialism. Rejecting emotionally based automatic responses, and the rationalizations that philosophers use to support them, leaves consequentialism as the best available option’ (p. 40). Thus, we can dispense with all the ‘intuition chasing’ that non-consequentialists have engaged in with endless trolley cases that supposedly demonstrate how people would resist, say, pushing a heavily weighted person onto the tracks to stop a runaway trolley from killing five other people – that is, would resist the option yielding better consequences. As de Lazari-Radek and Singer show, with the help of Greene's work, the trolley cases do not actually have that anti-consequentialist takeaway, since the resistance here appears to be to the physical act of directly pushing another person, not the sacrifice of one life to save five. When the case is presented differently, such that one need only flip a switch to sacrifice the one person, the results flip as well, with most people allowing that they would save the five.

In line with the powerful work of Kahneman and others spelling out the nature of dual-process theories of cognition, Greene interprets such results in terms of a conflict between automatic responses and responses based on a higher level of cognition. But, as the authors note, he does not conclude that

But for their purposes, de Lazari-Radek and Singer do not deem this much of a caveat. Whether the subject is Kantian views on sexual morality or anti-consequentialist views of retributive punishment (also largely Kantian), the evidence indicates that it is the consequentialists who are doing the thinking, rather than simply rationalizing their primitive gut reactions. As Singer observed in another context, when countering Bernard Williams's charge that utilitarians may have ‘one thought too many’ in situations calling for the sacrifice of their near and dear for the greater good, it is surely worse to have ‘one thought too few’ when it comes to ethics, however proudly such anti-consequentialists as G. E. M. Anscombe may have paraded their shortage of thoughts.

What is more, it is precisely this debunking gambit that de Lazari-Radek and Singer use to come to the aid of Sidgwick's utilitarianism (based on the principle of benevolence), which Sidgwick himself had worried was insufficiently defended in his work, ending up in the famous stand-off with rational egoism that he called the ‘dualism of practical reason’. Although the claim is more fully developed in The Point of View of the Universe, the authors do indicate how they ‘think it is possible to distinguish the intuitions that Sidgwick argued lead us to utilitarianism from the kind of automatic emotional responses that Green describes and debunks’ (p. 41). Rational egoism is an excellent candidate for such debunking, but rational benevolence is not, and its ability to withstand such evolutionary debunking arguments and appear rather as a product (like mathematics) of higher-order reasoning suggests a way to overcome Sidgwick's dualism. That is big news, but of course, there is a lot riding on the nature of reason and the defensibility of the cognitive intuitionism, or rationalism as Derek Parfit tended to call it, that could spell out why a non-debunked principle of benevolence could be deemed true, in some significant sense of the word. Demonstrating that it is genuinely clear and precise, able to withstand careful reflection, consistent with other apparently self-evident principles, and capable of winning a consensus of experts – these being the criteria that Sidgwick so forcefully set out, and that are endorsed by de Lazari-Radek and Singer – remains a pretty big project for the long philosophical haul.

A similar debunking strategy appears again in the excellent little chapter on the candidate value theories for interpreting the notion of ‘best consequences’. The classical utilitarians were committed to a hedonistic account of ultimate good (whether consistently, as with Sidgwick, or confusingly, as with Mill), but from G. E. Moore on, other options came to the fore, theories of ideal goods or value pluralism, and most prominently, desire or preference satisfaction accounts, of the type favoured by Singer's earlier self. The authors pay due court to Nozick's infamous Experience Machine objections to hedonism or any theory making value purely a matter solely of conscious experiences – Nozick's upshot being that it is important actually to be achieving or accomplishing important ends, not simply be floating in a tank with a brain wired to think that one is doing such things. How things are, not how they feel on the inside, matters. But here again, the research can insinuate doubt:

Thus, for all its popularity, the Experience Machine argument may not ‘provide reliable evidence that we want more than the best states of consciousness that we can have. In that case, to the question “What should we maximize?” the classical utilitarian answer – “pleasure” – remains defensible’ (p. 61). The more so, it seems, given the even more damning objections to the alternative accounts, which the authors expertly review.

But there is another important twist here. Despite that utilitarian slogan about ‘the greatest happiness of the greatest number’, the authors argue that it is important to tease apart happiness and pleasure, that happiness, as Daniel Haybron has argued, has more to do with a psychological disposition to positive emotional evaluations – ‘to be in a good mood, to be cheerful, to have a generally positive outlook on life, etc.’ (p. 63). But if happiness is a disposition, ‘it is not happiness itself that is of intrinsic value, but rather the positive feelings that it is a disposition to have’, these positive feelings being the kind of experiences counting as pleasures or enjoyments’ (p. 63). Hence, strangely enough, a more exact statement of the utilitarian principle would avoid the word ‘happiness’.

What the authors suggest on this count may sit uneasily with their guarded appeal, in their final chapter, to the ever-expanding field of happiness studies: ‘With more scientists working on measuring happiness and understanding what increases it, the idea of happiness as a fundamental goal of public policy is gaining support. Bentham would have been pleased’ (p. 117). Perhaps, but less so if he had had the opportunity to read de Lazari-Radek and Singer on the dangers of conflating happiness and pleasure. It may be a bigger assumption than the authors realize to take happiness, as variously measured in happiness research, as such a decisive and straightforward means to promoting hedonic experiences via public policy.

Still, the brilliant and rapid-fire rebuttal of the objections to utilitarianism, objections old and new, is effective overall. In the later chapters, the authors address everything from the charge that utilitarianism demands acting immorally to the charge that it demands too much altruistic sacrifice, from the charge that it ignores ‘the separateness of persons’ to the charge, or ‘repugnant conclusion’, that maximizing total utility could demand an enormous global population of people with lives worth living, however barely. Their rebuttals are sometimes along more familiar lines, but sometimes less so. Against the charge that utilitarianism might demand that we ignore our special obligations, as in the controversial example Godwin gave of how it would be better to rescue a great benefactor of humanity than one's own wife or mother from a burning building (assuming they were not such great benefactors), they rehearse and update the compelling utilitarian justifications (which Godwin himself came to endorse) for recognizing the importance of partial attachments:

But on the tangled question of just how self-effacing, even esoteric, a utilitarian approach might be, the authors take a much bolder and more provocative position:

Few utilitarians other than Sidgwick and de Lazari-Radek and Singer have followed the argument this far in this direction. And the authors would seem to have gone well beyond Sidgwick in that their utilitarian esotericism is hiding in plain sight, so to speak, there for all to see in a book that, unlike Sidgwick's Methods of Ethics, is aiming to be popular. There is a great deal more packed into this all too short volume – for example, very thoughtful remarks on utilitarianism and distributive justice, including the prioritarian alternative, as well as some serious grappling with the repugnant conclusion regarding population policies. But the difficult questions raised by the apparent gap between the medium and the message may end up provoking readers into wondering whether, on Sidgwickian grounds, they should welcome this work or not – even if it is the most sophisticated and thought-provoking introduction to utilitarianism produced in the last century, one that in its profusion of thoughts will challenge the critics for years to come. Hopefully to good effect.