In his engaging and challenging new book, From Morality to the End of Reason, Ingmar Persson sets out to identify the underlying principles and implicit assumptions of common-sense morality that generate what he calls its ‘asymmetrical’ features. He does this in order to argue that common-sense morality rests on false presuppositions and entails paradoxes and contradictions. He makes that argument, in turn, to clear the way for a wholly ‘symmetrical’ morality to put in the place of common-sense morality. Though Persson is reluctant to use the term, the result is a form of consequentialism.

Being the product of an extremely systematic thinker, this book is just one part of Persson's overall philosophical project, which is also importantly carried out in his 2005 book The Retreat of Reason and the 2012 book he co-authored with Julian Savulescu, Unfit for the Future, both of which Persson often refers to in his new book. This overall project is, or so I argue below, itself a little paradoxical. On the one hand, Persson argues that human reason is much more limited in its reach than many philosophers ordinarily think. Yet, at the same time, he also argues that human morality needs to become much more rational and symmetrical in nature. However, this apparent tension can perhaps be seen as being in line with the overall message of The Retreat of Reason. The main thesis in that book is that either we live in a way that maximally conforms our lifestyles to the dictates of reason and rationality at the cost of overall emotional satisfaction; or else we try to live in accordance with what best fits with our human emotions and sentiments, in which case we must offend against philosophically sophisticated reason. In now arguing, in his 2012 and 2013 books, that we should change our moral emotions using biomedical enhancements, and that common-sense morality must be replaced with a wholly ‘symmetrical’ and rational morality, Persson seems to come down firmly on the side of the just-mentioned dilemma he discusses in his 2005 book that favours rationality at the cost of our ordinary emotions, desires and sentiments.

So what are the ‘asymmetries’ of common-sense morality that Persson thinks offend against rationality? First, our duties to avoid intentionally bringing harms and evils upon others are usually thought to be much stronger than our moral reasons, which common-sense morality also recognizes, to be helpful towards others, and to participate in mutually beneficial cooperation with them. Second, it is also usually thought that, whereas we are strongly morally responsible for harms and evils that others suffer at our hands, we are less responsible – in so far as we are at all responsible – for harms and evils that people suffer at the hands of others. The ‘symmetrical’ morality Persson himself prefers is, as already mentioned, of a consequentialist sort that gives us two main duties: to counteract bad outcomes no matter how they come about and to promote good outcomes no matter how they come about (chapters 7 and 10). Persson also wishes to make us just as morally responsible for bad outcomes brought about by others as for any bad outcomes that are brought about by us ourselves (chapter 7). As Persson himself recognizes, this strongly offends against our ordinary moral sentiments. And it appears overly demanding. So how does Persson propose to convince us to sign up to his favoured moral outlook?

What Persson does first is to argue that common-sense morality is implicitly or explicitly committed to a ‘doctrine of negative rights’ and a ‘causally-based doctrine of responsibility’ (chapter 1). All the main asymmetries of common-sense morality can be traced to these two doctrines, neither of which withstands rational scrutiny. The former doctrine, as Persson interprets it, supposes that we have pre-conventional or ‘natural’ rights against others to the effect that they refrain from ‘interfering with us or our property’ (1). The latter doctrine understands our moral responsibility for outcomes (both good and bad) as being directly proportional to the causal contribution we make to the production of these outcomes. For reasons of space, I here mostly focus on the former.

At the heart of the doctrine of negative rights that Persson thinks constitutes the main core of common-sense morality are, he argues, a basic right to ‘self-ownership’ and a thesis according to which we have a right to anything that we are the ‘first occupants’ of (including our own bodies and psychologies). That common-sense morality has those two basic ideas at its core is, Persson argues, the main reason why its ‘doctrine of negative rights’ doesn't withstand rational scrutiny (chapter 2). According to Persson's first major argument against this supposed self-ownership, we can safely assume that, if we have property-rights to some whole, we also have property-rights to the constituent parts of the whole. If that's true, and we enjoy self-ownership, this would mean that we have rights to all the parts of which we are constituted, down to the smallest little micro-particles. This, however, clashes with the idea that we mainly have rights to the things of which we were the first occupants. We weren't the first occupants of the particles we’re made of. Nor were those parts autonomously transferred to us by any other party. The paradoxical implication: we supposedly own something (viz. our own bodies) whose parts we don't own (viz. the particles our bodies are made of) (pp. 50–2).

According to Persson's second main argument, common sense also assumes that we have property-rights to the fruits of our labour, which would entail that we also have property-rights to any fruits of our ‘sexual labour’, namely, any children we produce. But if parents have property-rights to their children, these children don't possess basic rights to their own bodies: they don't enjoy the self-ownership that (according to Persson) common sense treats as foundational. So our (supposedly) commonsensical ideas about what grounds property-rights contradict, or cannot be made to cohere with, our belief that we all own ourselves (pp. 60–1).

Common-sense morality, if this is right, entails paradoxes and contradictions: we own certain wholes the parts of which we don't own, and we both own and don't own our bodies (unless our parents autonomously transfer these to us in some way). If that is so, and the strongest duties of common-sense morality rest on this imagined self-ownership, we must reject the most stringent parts of common-sense morality. What remains, Persson concludes, are the much weaker duties of beneficence that, he thinks, are also part of common-sense morality. Luckily, these duties of beneficence do not contain or entail any paradoxes or contradictions. So they can serve as the basis of a rational morality.

Is it right, however, that common-sense morality essentially involves assumptions about natural rights to anything we are the first occupants of, and the ideas about self-ownership that Persson discusses and tries to refute? Another part of Persson's overall picture, which I have not yet mentioned, seems to tell against this analysis of the core of common-sense morality, namely, the idea that common-sense morality was, as he puts it, formed as a ‘pre-cultural product’ by human evolution to ‘promote the reproductive fitness of a group-living species of animal’ (p. 305). This, if correct, would suggest that anything that is a core element of common-sense morality should have appeared on the scene long before ideas about things such as natural rights, self-ownership and autonomous transfers of property got their foothold during the Enlightenment. That, if correct, would in turn mean that the sorts of ideas Persson tries to refute with the above-mentioned arguments are really beliefs and doctrines we might perhaps be caused to form by the much more basic attitudes or dispositions that form the real core elements of common-sense morality, but that they aren't themselves really part of the essential core of common-sense morality. If so, then what Persson's arguments mainly refute are not the core sentiments at the heart of common-sense morality, but rather certain beliefs that these sentiments have led some, but not all, of us to form.

Persson seems, then, to face a choice: either he backs away from his claim that the core of common-sense morality is a product of human evolution during hunter-gatherer times, in which case he can keep his claim that the core of common-sense morality involves certain beliefs about natural rights and self-ownership. Or he sticks with his claim that the heart of common-sense morality is a product of human evolution, in which case he must back away from the claim that its essential core are certain beliefs about natural rights and self-ownership. Since it is very plausible, as Persson himself argues, to think that common-sense morality involves various attitudes and dispositions that are products of our human evolution, it seems that Persson will have to revise his views about what the most basic elements of common-sense morality are. If so, he also needs new arguments for why we should reject the asymmetries of common sense in favour of the sort of symmetrical morality he favours.

If his argument is on the right track, Persson must accept that there are certain attitudes and dispositions at the core of our moral sensibilities that under certain circumstances can certainly lead us to form beliefs that entail paradoxes and contradictions, but which themselves are neither paradoxical nor contradictory in the sense in which beliefs, or the implications of beliefs, can be. What does this mean for Persson's overall argument? Well, in the last two chapters of his book, Persson argues that unless we can show that our most basic attitudes and dispositions depend on false beliefs, or themselves involve or entail paradoxes and contradictions, they are not open to rational criticism: we cannot, he argues, have reasons for or against our most basic attitudes and dispositions (chapters 11–12). Our reasons ‘run out’, Persson argues, once we get down to our most basic attitudes and dispositions (including our most basic belief-forming dispositions and our most basic emotions and desires): we must regard these basic attitudes and dispositions as being beyond rational criticism. They instead form the starting points for theoretical and practical reflection about what to believe and how to live. But if that is the case, then, by parity of reasoning, this should also mean that our most basic moral attitudes and dispositions are beyond rational criticism as well: that we also cannot have direct reasons for or against them.

That, I assume, is precisely why Persson tries to show that our most basic moral attitudes involve false presuppositions and entail paradoxes and contradictions. But, as I argued above, his claim that our most basic moral attitudes are products of human evolution seems to force Persson either to reject his own claims about what constitutes the core of common-sense morality, or else to accept that this core of common sense crucially depends on a set of more fundamental attitudes and dispositions that we have (which are part of our evolutionary heritage). Either way Persson seems to end up in a position where his views about what is beyond rational criticism should lead him to accept that there are certain basic moral attitudes and dispositions that are simply part of our basic psychological make-up as the particular kinds of beings that we are. And so it would seem that Persson would need to treat these (i.e. the attitudes and dispositions that give rise to the ‘asymmetries’ of common-sense morality he discusses) as basic elements or the starting points of practical reflection, rather than as the sorts of derivative attitudes that his theory of rational reflection admits as being among the objects of rational criticism. Either, then, Persson needs to adopt a different view of rationality (of the sort that, say, Derek Parfit defends) on which we can have attitude-independent reasons for or against our most basic attitudes and dispositions; or else he must accept our most basic moral attitudes and sensibilities as being beyond rational criticism, and as instead being among the given starting points that any philosophical theory of ethics needs to take into account and respect.

Now, as I noted earlier, Persson himself thinks – and argues for this view in his 2012 book together with Julian Savulescu – that we should change our basic dispositions and attitudes with the help of biomedical enhancements: we should do so in order to give us moral sensibilities and motivations that are ‘fit for the future’. But Persson would need, it seems, to argue for this attempted change from the basic attitudes that his view of rationality and reasons treats as the necessary starting points for any arguments and attempts at theory-construction: namely, our most basic practical attitudes and dispositions. Would Persson be able to give any non-question-begging argument for building that argument on those of our basic attitudes and dispositions that point in the direction of the symmetrical moral outlook he himself favours rather than on the sorts of shared basic attitudes and dispositions of ours that underlie the asymmetries involved in our commonsensical moral outlook? I don't see how he could do so. And so it seems to me that Persson needs to retreat to the sort of dilemma he puts at the centre of his 2005 book: either we try to be maximally rational in all aspects of our lives, in which case we must frustrate many of the values that are directly based on our common human emotions and sentiments. Or else we embrace these human values, in which case we must accept that there will be certain parts of our lives that on reflection can appear strangely ‘asymmetrical’ and, in certain respects, ‘irrational’. Within the philosophical constraints under which Persson is operating – with the restrictions on the reach of theoretical and practical reason he thinks we must accept – he cannot, it seems to me, have it both ways. He cannot both argue that morality should be hyper-rational and that our most basic attitudes and dispositions are beyond rational criticism.

This said, there is, I think, much to admire and agree with in Persson's new book. Among the arguments I haven't mentioned above are intricate discussions of the so-called act-omission doctrine and the doctrine of double effect, both of which are at the centre of many controversies in applied ethics and normative ethics more generally (chapters 3, 4 and 6). These arguments make a number of important and convincing points about these moral doctrines. Persson's above-mentioned arguments against self-ownership and natural rights also seem to hit hard against the sorts of philosophical systems that put such ideas at their foundations. There are also chapters on the nature of ‘mental explanations’ (chapter 5), what consequentialists should try to maximize (chapter 8), and non-transitivity and supervenience (chapter 9) that make a number of interesting and important arguments. So even if, as I have argued, Persson's philosophical outlook does not place him in a position in which he can avoid accepting much of common-sense morality as something given that we must simply accept his various arguments nevertheless do an impressive job at shaking the foundations of many philosophical attempts to develop and systematize the foundations of common-sense morality. This book, therefore, should be on the reading lists of any philosophers interested in those foundations.