Evolution and Utilitarianism

Abstract

Katarzyna de Lazari-Radek and Peter Singer have recently provided an evolutionary argument for utilitarianism. They argue that most of our deontological beliefs were shaped by evolution, from which they conclude that these beliefs are unjustified. By contrast, they maintain that the utilitarian belief that everyone’s well-being matters equally is immune to such debunking arguments because it wasn’t similarly influenced. However, Guy Kahane remarks that this belief lacks substantial content unless it is paired with an account of well-being, and he adds that utilitarian beliefs about wellbeing—e.g. the belief that pleasure is good and pain is bad—were probably shaped by evolution. Logically, de Lazari-Radek and Singer should therefore reject these beliefs along with the deontological beliefs that evolved. The present paper is a defense of their argument. After considering a number of unsuccessful replies to Kahane’s objection, I put forward a more promising solution: de Lazari-Radek and Singer should combine their objectivist view in metaethics with a subjectivist account of well-being, such as the desire theory. Such a hybrid account would tackle Kahane’s challenge because subjective accounts of value are immune from evolutionary debunking arguments. And it would be compatible with utilitarianism, which (as Kahane remarks) doesn’t fit very well with metaethical subjectivism. Before concluding, I deal with two concerns that this solution might raise: I argue that the desire theory is actually subjective enough to escape Kahane’s objection, and I deny that retreating to the combination of ethical objectivism and prudential subjectivism is ad hoc.

The Ethical Dilemma

Sharon Street (2006) famously raised a dilemma for ethical realism—understood as the view that there are objective, “stance-independent” moral truths. The challenge is based on what she takes to be a plausible assertion: given the impact that our moral beliefs have on our survival prospects, natural selection must have had a considerable influence on their content. No one believes that parents should exterminate their offspring, for instance, because this belief (would have) led its bearers’ genes to disappear. Instead, we believe that parents should take care of their progeny.

This observation poses a pressing question: What is the relation between the forces of evolution and moral truth? And it is unclear what realists should answer. They could certainly deny that there is any relation and say that we acquired our moral beliefs irrespective of their truth-value. But this would lead them straight to moral skepticism, argues Street. Absent a properly incredible coincidence we couldn’t have ended up having just the true moral beliefs via a process that is blind to moral facts (Street 2006: 121). Alternatively, realists could answer that our moral beliefs evolved precisely because they are correct, that evolution tracks moral truth. In this line of thought, it isn’t by accident that we make true moral judgments, for having a grasp on moral facts promoted the reproductive fitness of our ancestors. In Street’s opinion, however, this claim is empirically implausible assuming the truth of realism. Why would natural selection track stance-independent moral truths? Most plausibly, our moral attitudes were selected for simply because they helped our ancestors to survive. Call this the “ethical dilemma”.

This dilemma has generated a number of interesting replies (Wielenberg 2010; Enoch 2010; Parfit 2011; Shafer-Landau 2012), but I will focus on one in particular. Katarzyna de Lazari-Radek and Peter Singer (“LRS” hereafter, 2012) concede that most of our moral beliefs have an evolutionary explanation, from which they conclude that those beliefs are unjustified. Such is our belief that incest is wrong, since it resulted from a negative attitude to incest that evolved regardless of the wrongness of incest. Still, LRS deny that all moral beliefs are adaptive in this way. One particular belief that could hardly have evolved, they argue, is our belief in the principle of “universal benevolence” (“UB” hereafter), according to which we should grant everyone’s well-being equal consideration. We don’t owe this belief to the evolutionary advantage of the corresponding behavior. As a matter of fact, assessed in terms of the replication of our genes, this is a very bad belief to have: those who act on it will sometimes sacrifice their most vital interests for the interests of perfect strangers. On LRS’s view, we grasp the truth of UB just as we access mathematical truths: by using our rational capacities. Hence, unlike our belief that incest is wrong, our belief in UB is epistemically warranted.

LRS’s contribution to this debate should be read not only as a realist solution to the ethical dilemma but also as a positive argument for utilitarianism. Indeed, UB is at the very core of utilitarianism. It would be good news for utilitarians if it survived the evolutionary debunking. By contrast, most objections to utilitarianism are based on beliefs that were shaped by evolution. Thus, the objection that utilitarianism is too demanding rests on our belief that we have special duties to our relatives, the objection that utilitarianism sometimes requires punishing the innocent rests on our belief that punishment should be retributive, and the objection that utilitarianism does not issue the correct verdict in the trolley problem rests on our belief that pushing the large man is wrong. Assuming that these beliefs are unjustified because we owe them to an off-track process, the corresponding objections vanish. Utilitarianism may well be very demanding, allow for the punishment of innocents, and entail that we should push large men from footbridges, but this cannot be turned against it (Greene 2008; Singer 2005: 348). Pending a belief that is incompatible with utilitarianism and yet—in contrast with the three beliefs just mentioned—wasn’t shaped by evolution, LRS’s solution to Street’s dilemma seems to speak for utilitarianism.

In response to LRS’s case for utilitarianism, Guy Kahane (2014, 2011: 120) presents them with a challenge analogous to the ethical dilemma but based on the observation that most of our prudential beliefs were shaped by evolution too. The present paper takes up this challenge on behalf of LRS’s argument for utilitarianism. After presenting Kahane’s charge (Section 2), I discuss two unsatisfactory responses to it (Section 3). Then, I develop a better solution (Section 4) and deal with a couple of concerns that it may be thought to raise (Sections 5 and 6).

The Prudential Dilemma

For the sake of argument, Kahane concedes that our belief in UB wasn’t shaped by evolution. He nonetheless maintains that the principle is empty of content unless combined with an account of prudential value. Until one knows what well-being amounts to, the claim that everyone’s well-being matters equally will fail to guide our conduct. Of course, philosophers aren’t short of theories of well-being. But, the objection continues, most of our prudential beliefs were presumably shaped by evolution. Thus, in all likelihood, we believe that pleasure is good and pain is bad because seeking pleasure and avoiding pain helped our ancestors to survive (Kahane 2014: 331).

Now, this observation creates a worry that parallels Street’s question for moral realists: What relation do the forces of evolution bear to prudential truth? And there again arises a dilemma. If LRS deny that there is any relation, then they will be committed to well-being skepticism, the view that we never know what is good for anyone. Indeed, on the resulting view, we have the prudential beliefs that we do for reasons that are entirely unrelated to their truth-value, and it would be an extraordinary coincidence if these beliefs happened to be true. Suppose, by contrast, that LRS would answer that evolution tracks truth about well-being, that it led us to have the prudential beliefs that we have precisely because these beliefs are true. On such a view, it is no accident that we make true judgments about well-being, for having a grasp on prudential facts promoted the reproductive fitness of our ancestors. However, just like the corresponding reaction to the ethical dilemma, this answer is empirically implausible in light of prudential realism. Why would natural selection track objective prudential truths? Most plausibly our prudential attitudes were selected for simply because they led our ancestors to survive. Call this the “prudential dilemma”.

While the prudential dilemma is interesting in its own right, it also has consequences for LRS’s solution to the ethical dilemma. Given that UB must be combined with an account of well-being to deliver concrete ethical norms, it will secure proper moral knowledge only if prudential knowledge is possible. In order to complete their solution to the ethical dilemma, LRS must therefore solve the prudential dilemma as well. But the prudential dilemma raises an even more pressing difficulty for their defense of utilitarianism, which is my main concern in this paper. For some prudential beliefs were hardly shaped by evolution. Kahane mentions “the views that the good life consists of ascetic contemplation of deep philosophical truths” (Kahane 2014: 334, 2011: 120), and it is indeed difficult to see how an ascetic conception of well-being could have evolved. (One might also mention the masochistic belief that pain is good.) But then, assuming with LRS that our belief about incest is unjustified because it was shaped by evolution and that our belief in UB is justified because it wasn’t, we should conclude that the belief that pain is good and pleasure is bad is epistemically superior to the more usual belief that pleasure is good and pain is bad. This conclusion is in tension with utilitarianism, which involves—in addition to UB—a certain construal of well-being, according to which pleasure is good and pain is bad. Unless they can show that our belief that pleasure is good and pain is bad is immune to debunking, LRS’s argument will backfire on utilitarianism.

Bad Solutions

Before presenting my own rejoinder in Section 4, I will now examine two possible but unsuccessful replies to this challenge.

A Non-Debunking Explanation

To be fair, LRS had anticipated Kahane’s objection. In the piece to which he refers, they acknowledge that UB “needs a theory of well-being, or else it is empty of content” (LRS 2012: 27). Still, they don’t take the issue very seriously and are satisfied with “pointing out that if no theory of well-being … were immune to a debunking explanation, this would show only that no theory could be preferred over others on the ground that it alone cannot be debunked” (LRS 2012: 28). But, as we just saw, we are not in such a stalemate situation, since some of our prudential beliefs were not shaped by evolution.

More recently, LRS have granted the issue more attention. They now deny that our belief that pleasure is good and pain is bad was selected for:

To be motivated to seek pleasure and avoid pain, it is not necessary that we have the normative belief that pleasure is good and pain is bad. The way pleasure and pain feel is already sufficiently motivating. Hence, there is no reproductive advantage in our holding that belief. In this respect, it contrasts with, for instance, the normative belief that incest is wrong, for some people are motivated towards having sex with members of their family and the belief, especially when socially reinforced, will help to combat that motivation. (LRS 2014: 268–9)

But this reply is not fully satisfactory, for the case of pain and pleasure seems to be analogous to that of incest in this respect. Although most of us tend to avoid pain to the extent that we can, some—namely, masochists—don’t. And although most of us seek pleasure, some—namely, ascetics—don’t. This attests that, by themselves, the phenomenologies of pain and pleasure do not always suffice to have us avoid pain and seek pleasure. In light of this, there is no clear-cut contrast between the case of pain and pleasure, on the one hand, and that of incest, on the other. Undeniably, some people are tempted by incestuous intercourse (just as some are attracted by pain or uninterested in pleasure), so that the belief that incest is wrong may have helped them avoid incestuous intercourses. Still, most people feel a strong disgust at the mere thought of such behavior (just as we typically avoid pain and seek pleasure), and this basic repulsion is motivating to quite an extent. LRS’s rejoinder therefore tends to overgeneralize: if our belief that pleasure is good was not shaped by evolution, then neither was our belief that incest is wrong.

Moreover, in focusing on the specific claim that our belief that pleasure is good and pain is bad was selected for—and ignoring the vaguer contention that it was somehow influenced by evolutionary forces—, LRS fail to address the more fundamental point of Kahane’s objection. As far as their rejoinder goes, our belief that pleasure is good and pain is bad could have been shaped by evolution indirectly, without being itself an adaptation. For instance, it might be that evolution selected for a positive attitude to pleasure and a negative attitude to pain, and that our belief that pleasure is good and pain is bad would result causally from these attitudes. This belief would then be an evolutionary by-product rather than an adaptation. Yet, the worry would remain: this would amply suffice to ground a debunking argument, for we would still have acquired this belief via an off-track process—our positive attitude to pleasure and our negative attitude to pain were not selected for because pleasure is good and pain is bad (Kahane 2011: 111–2). Barring evidence that this belief was in no way subject to evolutionary influences, Kahane’s challenge is still awaiting for a solution.

Going Subjectivist

One might think that this leaves another option to utilitarians: going subjectivist. That way, they could escape both the ethical and prudential dilemmas. Indeed, subjectivists can easily accommodate evolution’s influence on our normative beliefs (Street 2006). Naïve subjectivism is a perfect illustration. Assuming that our normative beliefs are beliefs about our positive and negative attitudes, it is very plausible that they are true although they were shaped by evolution. These attitudes are evolutionary adaptations, and our normative beliefs represent them accurately. For instance, our belief that incest is wrong is correct because disapproval of incest was selected for and we know what we disapprove of. If evolution had selected for approval of incest instead, then we would approve of incest. Since we would know what we approve of, we would believe that we approve of incest or, in other words, that incest is right. And this belief would be true.

Kahane is quite pessimistic about this strategy, though. On his view, while UB is “logically compatible with antirealist views, [it is] extremely hard to defend once we accept a broadly Humean antirealist metaethics … on which moral truth is constructed out of our subjective attitudes and sentiments, including, presumably, the sentiments and intuitions underlying much opposition to utilitarianism” (2014: 339). Considering that our attitudes are far from being impartial, if they were to ground moral truths, they would hardly ground a principle as impartial as UB. Subjectivism is much more congruent with first-order moral theories that leave room for special duties than with strictly agent-neutral theories such as utilitarianism (Williams 1981).

Kahane even turns this critique of LRS’s argument for utilitarianism into an objection to utilitarianism. At the end of the day, we have to choose between two options neither of which is compatible with utilitarianism. We can go objectivist about normativity, and we will get UB (which survives debunking because the corresponding belief wasn’t shaped by evolution), but then we will be deprived of pleasure’s goodness (which does not survive debunking because the corresponding belief was shaped by evolution). Or we can go subjectivist, and we will get pleasure’s goodness (which is compatible with prudential truths being grounded in our attitudes), but then we will be deprived of UB (which is incompatible with ethical truths being grounded in our attitudes) (Kahane 2014: 339). The problem is that both UB and pleasure’s goodness are essential components of utilitarianism. So, it would seem that utilitarianism is no longer an option either way.

Although utilitarianism is admittedly incompatible with crude variants of subjectivism, one might reply that it is clearly compatible with more sophisticated versions. Ideal observer theories immediately come to mind. Suppose moral judgments were judgments about an ideal observer’s states of approval and disapproval. On the reasonable assumption that such an observer would approve of actions that maximize well-being and only of those actions, this would mean that an action is right if and only if it maximizes well-being. This seems to disprove Kahane’s claim that utilitarianism is in tension with subjectivism. However, the above assumption is reasonable only if the ideal observer is construed as impartial. Ideally informed and rational or not, a partial observer would not have perfectly utilitarian attitudes. But then, the worry is that impartial observer theories aren’t subjective enough to escape the ethical dilemma the way naïve subjectivism does. Naïve subjectivism can accommodate evolution’s influence on our moral beliefs because it takes these beliefs to be about our attitudes, which are evolutionary adaptations. But this explanation fails assuming that our moral beliefs are about what an impartial observer would approve of. Such an observer’s attitudes weren’t selected for by our evolution, and it is unclear how our belief that what she would approve of is right could have resulted from our own attitudes. In other words, there is a gap between our actual attitudes and those of an impartial observer, and this gap is precisely impartiality. In a sense, impartiality makes impartialist subjectivism too objectivist to escape the ethical dilemma.

Going Hybridist

All the parties in this debate seem to assume that a unified account must be given of the normative realm, that either all normative truths are objective or they are all subjective. One possible solution is to reject this assumption and stick to ethical objectivism while retreating to a subjective account of prudential value. On such a hybrid view, moral truths are true regardless of our attitudes, as opposed to prudential truths, which crucially depend on our stance. Torture’s wrongness doesn’t depend on anyone’s disapproval of torture, whereas pain’s badness depends on our dislike for pain. In the rest of this paper, I will not be able to provide a comprehensive defense of this solution. I will nonetheless give it some prima facie plausibility.

Such an account would escape the ethical dilemma in the manner suggested by LRS—some of our moral beliefs, including our belief in UB, are not amenable to an evolutionary explanation. But it would also escape the prudential dilemma. The prudential dilemma targets realist theories of well-being because they rest on an objective construal of prudential truth. Evolution had a great influence on our prudential beliefs, and objective theories of well-being have difficulty accommodating this influence. Subjective theories, by contrast, face no such difficulty. They have an account packed and ready: our positive and negative attitudes were selected for, and our prudential beliefs represent these attitudes accurately. We believe that pleasure is good because a desire for pleasure was selected for and we know what we desire. If evolution had selected for a desire for pain instead, then we would desire pain. Since we would know what we desire, we would believe that we desire pain or, in other words, that pain is good. And this belief would be true.

Of course, this solution will not be to the liking of hardline realists, who aim for an objectivist account of the whole normative realm. However, I am not defending realism against Street’s attack but utilitarianism against Kahane’s. And as a matter of fact, most contemporary advocates of utilitarianism already accept a subjective theory of well-being. This is notoriously true of preference utilitarians, according to whom a subject’s well-being amounts to the fulfillment of their desires. Things admittedly get trickier when it comes to hedonistic utilitarians, who equate well-being with pleasure. Still, even though some variants of hedonism are best described as objective, others aren’t. In this respect, Chris Heathwood draws a useful distinction between two conceptions of pleasure:

On the felt-quality theory, pleasure is a single, uniform sensation or feeling, in the same general category as itch sensations or nauseous feelings (only pleasant!). On the attitudinal theory, pleasure fundamentally is, or involves, an attitude—a pro-attitude that we can take up toward other mental states, like itches and nauseous feelings, or states of the world. (Heathwood 2014: 209; see also Sobel 2005: 443)

As Heathwood then observes, the felt-quality theory makes hedonism an objective view, because it entails that one thing is good for us whether or not we have a positive attitude towards it: our pleasure sensation. On the attitudinal theory, by contrast, hedonism is a subjective theory, for it identifies well-being with a positive attitude, which makes it plain that our well-being depends on our attitudes (Heathwood 2014: 209).

By combining metaethical realism with the desire theory or the attitudinal-theory variant of hedonism, the hybrid account not only provides an improved variant of LRS’s solution to the ethical dilemma; it also makes for a better argument for utilitarianism. Indeed, it allows both components of utilitarianism to survive debunking: our belief in UB escapes the ethical dilemma because it wasn’t shaped by evolution, and our belief that pleasure (understood as a sensation) is good escapes the prudential dilemma because it is made true by our positive attitude to pleasure. In the remaining two sections of this paper, I discuss two objections that could be leveled against this account.¹

Is Prudential Subjectivism Subjectivist Enough?

At first sight, our distinction between objective and subjective conceptions of well-being seems to make attitudinal hedonism and the desire theory subjective theories of well-being. A careful reader might nonetheless object that this is misleading. If an account of prudential value is subjective just in case it has prudential truths depend on our attitudes, then attitudinal hedonism and the desire theory are actually objective accounts of prudential values.

Let me illustrate this point with the desire theory. According to this approach, knowledge is good while sickness is bad because we want to know things but we don’t want to be sick. The truth of the sentences “Knowledge is good” and “Sickness is bad” is constructed out of our attitudes to knowledge and sickness. So far, so good. However, still according to the desire theory, it is not because we want our desires to be satisfied that desire satisfaction is good; the sentence “Desire satisfaction is good” is true regardless of our desires about desire satisfaction. The desire theory therefore implies that some prudential truths are stance-independent. As it turns out, the allegedly most typical instance of a subjective theory of well-being is objective and, a fortiori, constitutes a proper target for the prudential dilemma. This objection invites two replies.

Sometimes the best defense is a good offense. Proponents of the hybrid account could therefore challenge the objector with the following question: What kind of prudential truths must depend on our attitudes for a theory of well-being to count as subjective? Superficial truths such as “Knowledge is good” and “Sickness is bad” or more fundamental truths such as “What is good for a subject is the fulfillment of their desires”? The objector will run into troubles either way.

Whenever Kahane argues that our “core beliefs about well-being” were shaped by evolution, he appears to have in mind superficial prudential truths. Thus, on more than one occasion, he mentions the belief that pleasure is good and pain is bad (Kahane 2011: 120; 2014: 327, 329, 330, 331, 334, 339), sometimes along with other superficial beliefs, e.g. the beliefs that health is good and that death is bad (Kahane 2011: 120). But nowhere does he discuss beliefs in fundamental standards of well-being, such as the belief that well-being amounts to desire-fulfillment. Now, as long as he wishes to build his dilemma on the case of superficial beliefs, defenders of the hybrid account can simply deny that those beliefs are true irrespective of our attitudes towards their objects. Pleasure and health are good for us because we want to feel pleasure and to be healthy, whereas pain and death are bad for us because we don’t want to suffer and die. This is the subjectivist reply we discussed in the previous section.

The objector would therefore be better advised to direct their dilemma at the level of fundamental truths about well-being. These are seemingly stance-independent—the truth that something is good for a subject just in case she desires it, for instance, does not depend on anyone’s desires.² Yet, the prudential dilemma will be effective at this level only if fundamental beliefs about well-being were shaped by evolution too—if they weren’t, then they will not be debunked. So, did evolution select for a second-order desire for the satisfaction of our desires which then led us to believe that desire satisfaction is good? One might think it did. Imagine a creature with first-order desires shaped by natural selection that would also desire the frustration of these desires. Sometimes at least, her second-order desire would be efficacious, overruling her (per hypothesis) adaptive first order desires, thereby yielding less adaptive behavior. There must have been selection pressure against this, one might think. We evolved not to desire the frustration of our desires.³

Inevitably, this is quite speculative. So will be my reply. Assuming that evolution had a grip on our second-order desires, it must have selected against a general desire for the frustration of our first-order desires. This much must be granted. Besides, if evolution had had to select for second-order desires—either a desire for the satisfaction of our first-order desires or a desire for the frustration of our first-order desires—it sure would have gone for the first option. But the truth is it probably never faced such a “choice”. Most of the time, a second-order desire for the satisfaction of our first-order desires is superfluous, since the latter are already motivating to a large extent. There is a further reason to doubt that evolution selected for a general desire for the satisfaction of our first-order desires: from the evolutionary standpoint, not all our first-order desires should be satisfied—think of your desires for your best friend’s partner, food or money. It may therefore well be that evolution selected for desires for the frustration of some of our first-order desires. Again, this is all very speculative, but speculation is unfortunately the best we can hope for in this area.

Thus, while our belief that pain is bad presumably evolved, our belief that someone’s well-being consists in whatever satisfies their desires probably didn’t. More plausibly we acquired it by using our rational capacities, just as we acquired our belief in UB. Evolution selected for our capacity to have desires, and for some first-order desires that were essential to our survival. And then, as our cognitive capacities became increasingly complex, we started to form prudential beliefs in line with these desires: as we desired pleasure, we started believing that pleasure was good; as we desired health, we started believing that health was good; and so on. Generalizing on the basis of such examples, we then naturally came to believe that something is good for a subject just in case it satisfies their desires. The prudential dilemma is thus not clearly more threatening at the level of fundamental prudential truths than it was at the level of superficial prudential truths.⁴

Is the Retreat to Prudential Subjectivism Ad Hoc?

Assuming that the hybrid account can explain natural selection’s huge influence on our prudential beliefs, one might still worry that its retreat to prudential subjectivism is ad hoc. Consider an analogy. Some evolutionary psychologists maintain that religious faith is an adaptation, that we are disposed to believe in God because this helped our ancestors to survive and reproduce (Johnson and Bering 2009; Dennett 2006). On this view, we have the religious beliefs that we do for reasons that have nothing to do with their truth. Still, it would be foolish to infer from this genealogy that the beliefs in question are subjective, that the truth of the sentence “God is omniscient,” for instance, depends on our positive and negative attitudes to God. Whether purported religious truths are objective or subjective is a matter of their semantics and consequently must be established by investigating religious discourse and concepts. Clearly, we cannot fall back on “religious subjectivism” in order to avoid religious skepticism. Such a move would be ad hoc. An analogous concern might be raised against the present strategy. After all, whether purported truths about well-being are objective or subjective cannot depend on their being explainable by evolution or on our willingness to avoid prudential skepticism. Rather, it is a matter of the semantics of prudential judgments and must therefore be established by investigating prudential discourse and concepts.

To some extent, this objection is on the right track: the hybrid account would be ad hoc if there were no independent evidence that prudential truths are subjective while moral truths are objective. But this proviso should not be taken for granted. For there is evidence that prudential truths depend on our attitudes, starting with Peter Railton’s famous argument from alienation. As Railton puts it in an oft-quoted passage:

It does seem to me to capture an important feature of the concept of intrinsic value to say that what is intrinsically valuable for a person must have a connection with what he would find in some degree compelling or attractive, at least if he were rational and aware. It would be an intolerably alienated conception of someone’s good to imagine that it might fail in any such way to engage him. (2003: 47)

Objective theories of well-being are committed to the view that, in principle at least, some things could be good for us although we do not desire or enjoy them at all—and although we wouldn’t do so even if we were perfectly informed and consistent. This implication hardly fits with our ordinary conception of well-being. That subjective accounts are not alienating in this way provides them with a significant advantage.

Notice that this is no reason to opt for a subjective theory of normativity as a whole. For it is the source of an apparent disanalogy between our prudential and moral judgments. On the face of it, when we assert that something is good for a subject we presuppose that they have certain desires, but we assume nothing comparable when we judge an act to be wrong. Consider Charles Manson’s career as a serial killer. In order to know whether this way of life was good for him, we would arguably need to investigate his mental life. By contrast, we must lead no such inquiry to ensure that what he did was wrong. Whereas prudential objectivism seems to be intolerably alienating, moral objectivism doesn’t. Sure enough, this appearance of a disanalogy may be deceptive, but it is definitely on the side of the hybrid account, and this should suffice to defeat the charge that this account is ad hoc.

Furthermore, hybridism is in keeping with a respectable tradition in normative theory: that which draws a sharp line between moral and prudential duties in terms of categoricity. Thus, Immanuel Kant famously argued that a subject’s moral duties in no way depend on her desires (or ends), that they are categorical (1993: Sec. II; see also Mackie 1977; Joyce 2001). By contrast, he maintained that a subject’s prudential duties are hypothetical; they do depend on her attitudes. On such a view, prudential duties are constructed out of our attitudes, while moral duties aren’t. In other words, prudential truths are subjective, while moral truths are objective.

Conclusion

LRS’s input to the debate on evolutionary debunking arguments is in the strict continuation of Singer’s earlier defense of utilitarianism (e.g. 2005). Deontological beliefs have an undermining causal history, which they do not share with utilitarian judgments. As a result, the latter are epistemically superior. I have supported this argument against an objection by Kahane to the effect that the utilitarian construal of well-being is subject to the same kind of debunking challenge LRS address to deontological beliefs. I have argued that the argument is safe, as long as it rests on a hybrid conception of value that combines ethical objectivism with prudential subjectivism. Of course, I did not provide a complete defense of hybridism, which was beyond my ambition in this contribution. Not to mention the fact that some philosophers have already defended such accounts much more cleverly than I could have anyway. Nevertheless, I hope to have put forward a plausible rejoinder to Kahane’s objection.