Abstract

Joint practical deliberation is the activity of deciding together what to do. In this dissertation, I argue that several speech acts that we can use to alter our moral obligations – promises, offers, requests, demands, commands, and agreements – are moves within joint practical deliberation. The dissertation begins by investigating joint practical deliberation. The resulting account implies that joint deliberation is more flexible than we usually recognize, in two ways. First, we can make joint decisions not only about what we will do together, but also about what you or I will do alone. Second, we can deliberate by means of two distinct methods: propose-and-ratify, in which a proposed joint decision must be explicitly accepted to come into effect, and propose-and-challenge, in which a proposed joint decision comes into force unless it is explicitly challenged. Varying these parameters generates a botany of different kinds of proposals we can make within joint deliberation. When we look at these proposals more closely, we make a surprising discovery: for each kind of proposal we can make in joint practical deliberation, there is an everyday speech act with the very same properties. A certain kind of proposal to make a joint decision regarding one’s own actions has the same normative effects, under the same conditions, as a promise. One kind of proposal to make a joint decision regarding one’s addressee’s actions has all the essential features of a command; another kind of deliberative proposal – with the same content but a different method of evaluation – looks exactly like a request. And so on. These similarities are too systematic to be coincidental. The only explanation, I argue, is that these ordinary speech acts are identical to their doppelgängers within joint practical deliberation. Promises and offers are proposals to make joint decisions about what I will do. Commands, demands, and requests are proposals to make joint decisions about what you will do. And agreements are joint decisions about what we will do. Call this the deliberative theory of these speech acts. Considering each speech act in turn, I defend the deliberative theory by arguing that it provides a uniquely powerful explanation of its targets’ social and moral significance. Once we see how naturally these speech acts fall out of our practice of joint deliberation, theories that treat them as sui generis – as many moral philosophers now do – will come to seem redundant and nonexplanatory. Conversely, thinking of promises, offers, commands, demands, requests, and agreements as moves within joint practical deliberation allows us to give an elegant and generative theory of these phenomena that have confounded moral philosophers for so long.