Promises and Consent: The Moral Permissibility of Accepting a Promise to Perform an Act That Requires Contemporaneous Consent

Graduate Finalist paper in the 2025 National Uehiro Oxford Essay Prize in Practical Ethics. By Arjan Heir, University of Cambridge.

Promises are forward looking; they create a duty to act as promised in the future that the promisor cannot readily revoke. In contrast, although one may arguably consent in advance to some acts, morally valid consent to other acts, such as sex, requires that one consent to the act when it occurs (Dougherty 2013, 2018). If consent is prospectively granted to these types of acts, the consenting party has the right to revoke consent at any time and the other party ought to confirm that the prior consent still stands before proceeding. A promise to perform an act that requires consent in the moment, therefore, seems morally problematic. Under prevailing theories of promising,[1] promises may contain inappropriate content that trigger a duty on the part of the promisee to reject the promise. For Hallie Liberto, promises to perform acts that require contemporaneous consent fall within this category.[2] However, I argue that it is morally permissible to accept a promise to perform an act that requires contemporaneous consent. Furthermore, the promissory duty created by such promises is not rendered meaningless by its being conditional.

I.          The Problem with Sexual Promises

Consider the following hypothetical:

Football Game: Sam promises Joe that she will have sex with him if Joe’s team wins the game.[3]

            A sexual promise is a paradigmatic example of a promise that seems intuitively morally problematic because it involves an act that requires contemporaneous consent. Like Liberto, I will focus on sexual promises because the cost associated with non-consensual sex is high, the cost associated with non-performance (i.e., frustration of a partner’s sexual desire) is low, and there is no independent moral right to sex with a particular person (Srinivasan 2021). That said, the logic of the argument applies to promises involving other acts requiring contemporaneous consent, such as promises to donate an organ.[4]

As a preliminary matter, one might think that sexual promises constitute promises to perform an immoral act and therefore create no promissory duty. For Shiffrin (2011), it is beyond a promisor’s power to create a moral duty in herself to perform an immoral act merely by promising to do so. However, sexual promises do not contain immoral content and, therefore, surely create a promissory duty. Unlike, for example, a promise to kill another, it is usually not immoral to perform a sexual act. Thus, even if one believes that promises to perform immoral acts are morally invalid, sexual promises are valid promises. Others, such as Owens (2016), argue that promises are valid regardless of whether their content is moral or immoral. Again, it would follow that promises like Football Game are morally valid.

Given that a promisor can successfully make binding promises with sexual content, the intuitive reaction is that the promisee has a moral obligation to release the promisor from the promissory duty.[5] That is, in Football Game, Joe should not hold Sam to her sexual promise should the antecedent condition obtain (i.e., Joe’s team wins the game). In The Problem with Sexual Promises, Liberto offers an explanation for this intuition. A promise confers the promisee with power over the promisor. By making the promise, the promisor alters “the moral landscape of permissions and obligations” (Shiffrin 2008, 500–01). Importantly, the promise constricts the range of morally permissible options that the promisor has available to her. As a corollary, the promisee is imbued with the power to hold the promisor to her promise—thereby limiting her decisional freedom—or release the promisor from her promise—expanding her range of morally permissible options. Indeed, the point of a promise is to give the promisee a claim against the promisor that she would not otherwise have. At least at the time of performance, a promise “involves substituting another person’s discretion for one’s own” (Liberto 2017, 395). Since the promisee decides whether to release the promisor from her promise, the promisee exercises some discretional control over whether the promisor ought to perform the promised act. As Owens (2006, 51) puts it, the promisee has an “authority interest” over the promisor’s decision. Promise breaking is wrong, according to Owens, because the promisor does not respect the promisee’s moral authority over her conduct.

Liberto contends there are some domains in which it is impermissible to exercise control over another’s conduct. She terms promises that confer decisional power to another in inappropriate domains “overextensive promises” (2017, 386). Liberto argues that the recipient of an overextensive promise is morally obliged to reject the promise. That is, it is impermissible to be “the decider” of certain important choices in others’ lives (396). For example, suppose that a friend voluntarily promises you that she will have a child. Assuming your friend is cognitively capable, she ought to make the decision about whether to have children herself. You may offer advice to help her reach a decision, but you should not unduly sway her decision-making by holding her to the promise. If your friend decides that she does not want children, that option should be entirely available to her. Moreover, in Liberto’s view, the option to not have a child should not be incumbered by the spectre of breaking a promise. By accepting the promise and holding her to it, you retain normative authority over a decision that you ought to not control.

Likewise, it is inappropriate to accept decision-making power over others’ sexual choices. For Liberto, one’s decision-making freedom should not be hampered by promissory duties in situations like Football Game. In other words, sexual promises are overextensive. The promisee decides which options are available to the promisor, namely, whether the promisor may refuse to perform and also not wrong the promisee. By failing to reject an overextensive promise, the promisee impermissibly leaves the promisor with two options: (1) perform even if she would not otherwise, in order to keep her promise, or (2) refuse to perform at the cost of breaking a promise and wronging the promisee.

II.        A Response to Liberto

Few promises are absolute. Although promises are often made without qualification, conditions are almost always implied. W. D. Ross (1939, 98) highlights that everyday promises cannot be interpreted literally and, instead, are subject to “implied conditions and qualifications.” Put differently, “promises generally don’t result in a blank cheque of the promisee to your doing as promised, but seem importantly conditional” (Riedener and Schwind 2022, 2). Virtually all promises have implicit in-built conditions (Hart 1961, 136); sexual promises are no exception. A sexual promise—without further elaboration—should not be interpreted as a promise to have sex under any circumstances. It seems psychologically unrealistic that one would voluntarily incur an obligation to have non-consensual sex. Instead, it is more probable that a sexual promise is narrower than it appears at first blush. In my view, when one says, “I promise to have sex,” her promise may be more accurately interpreted as “I promise to have sex provided that it would be consensual, even if there are other attractive activities available to me.”[6]

A sexual promise is, therefore, a conditional promise and “if the antecedent condition is unfulfilled . . . it is just as if no [promise] had been made” (Dummett 1959, 150). The promisor has no promissory duty to have sex (or do anything else) if she does not consent. One may object that a sexual promise conditional on consent is no promise at all. Liberto advances this argument:

However, it is probably not the case that [the parties] hold a mutual understanding that her promise does not hold in the event that she changes her mind and does not want to have sex. Otherwise, there would be no point to having made the promise in the first place—nor could it have truly counted as a promise (2017, 392).

However, implicit conditions that exempt performance do not strip promises of their normative force (Holton 2010). For Raz (1999), a promise functions to prevent the promisor from acting on certain first-order reasons to act that would otherwise be available. In other words, the promisor surrenders some reasons that she could ordinarily use to justify her choice of action (Shiffrin 2008; Molina 2019). To illustrate, a person is usually entitled to decline to mow another’s lawn if she would prefer to read a book. Yet, if she promises to mow the lawn, she is no longer morally entitled to refuse to do so merely because she would prefer to read a book. Morally speaking, that reason is no longer available to her to justify the decision to not mow. Similarly, in the context of sexual promises, simply preferring another activity over consensual sex does not dissolve the promissory duty. In this connection, consider another variation of the Football Game hypothetical in which Joe’s team wins and Sam is enthusiastic about the prospect of performing her sexual promise. However, Sam is equally enticed by the prospect of spending the evening at a gathering with her friends to celebrate the team’s win. Here, Sam’s promise may prevent her from using her desire to attend the gathering to justify not performing the promise to Joe. Thus, a sexual promise is not meaningless even if it the promissory duty is contingent on the promisor’s consenting to sex at the time of performance.

Moreover, one may object that if the promisor prefers another activity, then she necessarily does not consent to sex. If that is true, then the antecedent condition would seem to fail whenever the promisor preferred an alternate activity, and the promisor would not be subject to the promissory duty. In my view, this objection conflates the distinction between (i) the promisor withholding consent as a matter of fact and (ii) whether the promisor is morally entitled to withhold consent. For sexual promises, the promissory duty is not conditional on the promisor saying, “I consent” (or providing another token of consent). Rather, the promissory duty is conditional on the promisor not impermissibly withholding consent. As discussed, a sexual promise cuts off, normatively speaking, certain reasons for withholding consent, viz., merely desiring another activity more. Thus, a promisor may withhold consent as a matter of fact if she prefers another activity, but it does not follow that she has withheld consent on a permissible ground.

At first blush, it is counterintuitive to think that there are morally impermissible reasons to withhold consent. Indeed, ordinarily one is morally entitled to refuse to have sex for any reason, or no reason at all. Yet, in other domains, it seems clear that it may be morally impermissible to withhold consent. For example, one may not consent to donating his blood, but we may very well think that he ought to consent given the minimal cost to himself and the dire need of the recipient. In making a sexual promise, the promisor deprives herself of a reason (i.e., preferring another activity) that would otherwise be entirely sufficient to justify her decision to not consent. There are of course alternative grounds to permissibly refuse to consent, including if sex would compromise bodily integrity or another fundamental right. Thus, the relevant question for purposes of determining whether the antecedent condition is fulfilled is: would the promisor consent but for her consideration of a normatively inaccessible reason (i.e., preferring another activity)? If so, the promissory duty stands even if the promisor does not provide actual consent.[7]

III.       Conclusion

In summary, using the paradigmatic example of sexual promises, I have argued, contrary to Liberto, that promisees may permissibly accept promises involving acts that require contemporaneous consent. Sexual promises are conditional on the act being consensual at the time of performance. If the promisor permissibly withholds consent, then an antecedent condition of the promise is failed and the promisor has no promissory duty to perform whatsoever. If the antecedent condition is satisfied, then the promisor is indeed subject to a promissory duty to perform and the promisee does not have a moral obligation to release the promisor from the promise.

References

Anscombe, G. E. M. Ethics, Religion and Politics. Oxford: Blackwell, 1981.

Dougherty, Tom. “Sex, Lies, and Consent.” Ethics 123, no. 4 (2013): 717–44.

— — —. “Affirmative Consent and Due Diligence.” Philosophy & Public Affairs 46, no. 1 (2018): 90–112.

Dummett, Michael. “VIII.—Truth.” Proceedings of the Aristotelian Society 59, no. 1 (1959): 141­–62.

Hart, H. L. A. The Concept of Law. Oxford: Clarendon Press, 1961.

Holton, Richard. “The Exception Proves the Rule.” The Journal of Political Philosophy 18, no. 4 (2010): 369–88.

Hume, David. Moral Philosophy. Edited by Geoffrey Sayre-McCord. Indianapolis, IN: Hackett Publishing Company, 2006.

Kukla, Quill R. “A Nonideal Theory of Sexual Consent.” Ethics 131, no. 2 (2021): 270–92.

Liberto, Hallie. “The Problem with Sexual Promises.” Ethics 127, no. 2 (2017): 383–414.

Molina, Crescente. “Is There Value in Keeping a Promise?” Journal of Ethics and Social Philosophy 15, no. 1 (2019): 85–90.

Owens, David. “A Simple Theory of Promising.” Philosophical Review 115, no. 1 (2006): 51–77.

— — —. Shaping the Normative Landscape. Oxford: Oxford University Press, 2012.

— — —. “Promises and Conflicting Obligations.” Journal of Ethics and Social Philosophy 11, no. 1 (2016): 93–108.

Rawls, John. A Theory of Justice. Revised ed. Cambridge, MA: Belknap Press, 1999.

Raz, Joseph. “Incommensurability and Agency.” In Incommensurability, Incomparability and Practical Reason, edited by Ruth Chang, 46–66. Cambridge, MA: Harvard University Press, 1997.

— — —. Practical Reason and Norms. Oxford: Oxford University Press, 1999.

Riedener, Stefan, and Philipp Schwind. “The Point of Promises.” Ethics 132, no. 2 (2022): 621–43.

Ross, W. D. Foundations of Ethics. Oxford: Oxford University Press, 1939.

Scanlon, T. M. What We Owe to Each Other. Cambridge, MA: Harvard University Press, 1998.

Shiffrin, Seana Valentine. “Promising, Intimate Relationships and Conventionalism.” Philosophical Review 177, no. 4 (2008): 481–524.

— — —. “Immoral, Conflicting and Redundant Promises.” In Reasons and Recognition: Essays on the Philosophy of T. M. Scanlon, edited by R. Jay Wallace, Rahul Kumar, and Samuel Freeman, 155–78. New York: Oxford University Press, 2011.

Srinivasan, Amia. The Right to Sex: Feminism in the Twenty-First Century. New York: Farrar, Straus and Giroux, 2021.

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[1]              Three accounts of promising have predominated: normative power accounts (Raz 1997; Shiffrin 2008; Owens 2012), expectation accounts (Scanlon 1998; Anscombe 1981), and conventionalist accounts (Rawls 1999, 303–08; Hume 2006, 110–23). For purposes of this paper, the theory to which one subscribes is immaterial.

[2]              Liberto focuses on sexual promises, but her argument can apply to other acts requiring contemporaneous consent.

[3]              Adapted from Liberto.

[4]              The intuitive reaction against the moral permissibility of accepting a promise to donate an organ may not be as strong as the intuitive reaction against sexual promises. One might contend that it is permissible to accept an organ donation promise, given one may have pro tanto moral reasons to donate an organ independent of a promise. Regardless, if the argument in favour of sexual promises succeeds—where the intuitive reaction against permissibility is strongest—then the argument succeeds with respect to similar promises, including organ donation.

[5]              I set aside the question of whether the promisor acts immorally by making sexual promises.

[6]              I take the position that parties may permissibility (and often do) have sex when there are more pleasurable alternatives available (Kukla 2021).

[7]              Of course, actual consent is required for the promise to permissibility act.