Review Philosophy

Saying and Doing

About: Vincent Boyer, Promesse tenue. Agir par devoir, Classiques Garnier

by Philippe Saltel , 9 January
translated by Arianne Dorval
with the support of

Why do we make promises? And what motivates us to keep those we make? Are there good reasons for breaking commitments? Promises, the foundation of our social relationships, are an enigma. Vincent Boyer helps us get to the bottom of this.

Why do we keep promises? The question is, in truth, a puzzling one. If we honor them for reasons other than “having promised”—for instance, out of self-interest—promises lose their categoricity, binding only those who believe them. However, if our reason for acting is that we must accomplish what we have promised to accomplish, then why must we? How can one justify acting out of duty simply because it is duty? Such is the “enigma” of the motive behind categorical obligations like the promise, bearing in mind that the general case of “reasonable” fidelity to commitments is accompanied by rarer, but undeniable, cases of justified transgression (missing an appointment to save a life) and, conversely, of contentious discipline (incurring major danger, handing over money to someone who will misuse it).

A Theoretical and Practical Investigation

It is to this question that Vincent Boyer devotes his investigative work. The book begins with a scrupulous review of the great moral theories that have taken up the question of the categoricity of promises (utilitarianism, Hume’s skepticism, Kant’s theory of duty), before considering the practice of promise-making itself (What does one do when making a promise? What obligation follows from the promise?) in a final analysis of the linguistic, institutional but also “natural” facts at play in the practice as it is and as it enables its most common implementation. This “neo-Aristotelian” moment, supported by contributions from Elizabeth Anscombe, Philippa Foot, Michael Thompson, and Vincent Descombes, leads to the proposal to combine, against intuition but not without good reason, a moral naturalism (whereby promises serve a human good) with the need for institutions wherein such a language game takes on meaning and can be taught to the young through the use of prohibitive verbs that set limits to their freedom of action.

Is the Obligation of the Promise Relative, Artificial, or Unconditional?

Boyer rightly notes that many works of moral philosophy have adopted, following Henry Sidgwick’s book The Methods of Ethics (1874), a “comparative strategy” of classifying and evaluating ethical theories so as to justify one of them. His own work, however, escapes this criticism. Insofar as it is devoted to the specific question of the categoricity of promises, it does not compare theories from a broader perspective in order to contest their principle, but rather identifies their contribution and their limits as part of the investigation. In the same vein, one of the merits of this philosophical work—and not the least—is that it challenges the dichotomies and classifications that pit utilitarianism against deontology, recognize no teleological dimension in Kantianism, or force the Humean text into the contemporary distinction between three major types of normative ethics (depending on whether these center on the agent, on the act, or on the consequences of the act).

To be sure, utilitarianism has put forward a plausible motive for a large number of transgressions, these being justifiable by the pursuit of a greater good. For act-based utilitarianism, however, the duty to seek the best effects in every situation abolishes all obligatory dimensions of a given word. As is well known, for rule-based utilitarianism, the good consequences of respecting certain imperatives (e.g., the obligation of the promise) outweigh their disadvantages. Yet, such an orientation can appear as a form of “rule fetishism, in which case it is no longer distinguishable from act-based utilitarianism, even as it is more flexible and admits of exceptions. For its part, Hume’s theory of artificial virtues differentiates these from natural virtues: While the latter directly produce a good (e.g., benevolence), the former, which are more complex, are only effective through their overall system (e.g., justice). With this theory, Hume proposed what Boyer rightly calls “a genesis of the categorical” (p. 113). The Scottish philosopher highlighted the unintelligibility of promises prior to all conventions, thereby distinguishing, for all future investigation, between the question of the nature of a promise and that of its obligation. However, bound by his “undoubted maxim” (p. 132) that all action is the sign of a motive and therefore that no action can be virtuous without this prior motive, he could find no other motive for just actions than self-interest. This led him to ground the categoricity of promises (which are necessary to social life) in a useful “fiction” (p. 164), a “feigned desire to oblige” (p. 172) associated with the spoken word which makes one forget the true motive of a promise and ignore its intrinsic value.

It is true that the philosophy of duty, such as we find in Kant, ultimately restores duty to its rightful place (so to speak), particularly in relation to promises. According to this position, the motive of duty is not a fiction, nor a fortiori is it a motive for assistance when virtue is insufficient. However, the position comes with a number of drawbacks: The difficulty of explaining why the motive of duty must prevail over any other, the correlative devaluation of benevolence, and the exclusive attribution of a “moral content” (p. 260) to certain actions only. All in all, the three philosophies that have taken up the question of the promise and are being defended or criticized in the contemporary community (which is largely present in the book) have contributed to clarifying the problem without really being able to solve it. Boyer’s work offers a wide-ranging and precise analysis of these theoretical perspectives as they are interpreted today, which allows him to determine the purified form of the question. The latter is dealt with in the fourth and final chapter and constitutes the author’s proposal.

The Conditions of a Practice: Making and Keeping Promises

This proposal, inspired by Wittgenstein, is then developed using an approach that is the reverse of the previous one: The study of how far-reaching moral theories conceive of the practice of promise-making gives way to the project of constituting a theory from the practice itself. This does not mean that the author accomplished his precedent work in vain, since in doing so he set the terms of the problem, and in particular the order of questions, which we owe to Hume: What is a promise? How does it oblige us?

It is therefore not just a matter of thinking the immunity of promises to changes in circumstances—their primary categoricity—but also of considering fidelity as a virtue and the promise as a “duty of virtue”: For this purpose, Boyer essentially builds on Anscombe’s philosophy of action and Foot’s moral thought in three successive stages.

Hume considers that promises are “naturally unintelligible” (p. 296), and indeed that no private will can explain this/them, insofar as obliging oneself obliges one to nothing so long as the obligation does not take on a social dimension. While according to Hume self-interest leads us to “act as if,” the Anscombian theory of intention allows us to consider both the knowledge of what we do and our will to do it—which together constitute the intention to act—as essential to the promise. This theory highlights objective conditions: We promise what we can promise, what we have reason to promise, what the recipient of the promise has reason to accept, and so on. Yet, this is all a game, a “language game” (as per the title of the last chapter): To think that we are making a promise and to make a promise is to respect certain rules of the promise as such, the spoken terms of which can be modified without changing the rule.

That said, there exist many other language games, and the question of the binding character of promises is not settled in this way: How, then, do admittedly conventional signs engender an obligation? Hume’s answer is well known: Certain words express—allow us to feign—the desire to oblige. However, this is not enough, for the reasons above and because promises are classified as a kind of hypothetical imperative, which they are not in concreto. Leaving the semantic terrain, Anscombe suggests that one learns to oblige oneself through assimilating prohibitions (“stopping modals”) as part of one’s childhood education, a kind of compulsory learning of the rules of the game. Though clearly less original than other propositions made by this disciple of Wittgenstein, this idea evokes the taboos, rules of politeness, manners, and practices of non-violence and negotiation that have been examined by philosophers of education, including classical ones, and by modern and contemporary anthropology.

Even more classic is the book’s final distinction between absolute (logical, physical) necessity and moral (Foot) or practical (Descombes) necessity. For necessity (which, since Spinoza, is not to be confused with constraint) can be derived, that is to say, attached to a good that it renders accessible, without being absolutely binding: a necessity that can be undone once the good pursued has been attained or degraded to a lower plane. Is it really necessary to read the Prolegomena after one has read the first Critique? Is this journey as imperative as it once was? While one could abandon a necessity of this kind, doing so would, as Descombes writes, deprive one of a good, of a certain, important, very important, more or less important good... It is nevertheless in this sense that Boyer, drawing on Philippa Foot’s Natural Goodness which he nicely describes as “a little treatise on non-Foucauldian social philosophy” (p. 345), conceives promises as instruments of a specifically human good that enables people to oblige each other, to make others do certain things within an egalitarian framework, namely that of conventions based neither on inequality of power nor on threats or rewards.

This is the reason why the agent who does not keep his or her promises must give the reasons for his or her defection: not because promises are by nature absolutely binding and not because they are always subject to an estimate of their probable outcome, but because fidelity and the trust that goes with it have their place in an order of goods that obliges us without constraining us, for such is also the property of human virtues and their constantly renewed arrangement. Boyer has thus convincingly analyzed the contextual and social conditions of the promise as a language game, the conditions of its learning, and the link between promises and a human good that sometimes resides solely in fidelity. This combination of a “conventionalism à la Hume” and a “naturalism à la Aristotle” (p. 368) is an original and courageous proposal, patiently developed at the end of a book that is very rich in references, quotations and examples, which makes it highly accessible and of great pedagogical quality, while being also very rigorous, precise, and demanding in its argumentation, which makes it useful for the progress of moral philosophy.

Vincent Boyer, Promesse tenue. Agir par devoir, Paris, Classiques Garnier, coll. « Philosophies contemporaines », 2021, 394 p., 39 €.

by Philippe Saltel, 9 January

To quote this article :

Philippe Saltel, « Saying and Doing », Books and Ideas , 9 January 2024. ISSN : 2105-3030. URL :

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