John Deigh compares Hume’s conventionalist account of promises against Scanlon’s principle-based account and argues that Hume comes out ahead.
Specifically, Deigh argues that Scanlon has difficulties explaining how promises could generate obligations in conditions where people do not generally trust one another, such as in war.
Roughly speaking, Scanlon treats the obligation to do what we promise as one instance of a broader set of obligations against misleading others. Going back on a promise is just one special case of misleading another person about what you intend to do.
Deigh argues that promises in war time are obligatory even though the obligations of truthfulness do not apply. Armies can deceive one another but they are also capable of binding themselves by promises to surrender. As Deigh sees it, this is possible because promises are established by conventions: if you give the conventionally understood signs, you have made a promise.
Scanlon, according to Deigh, is committed to thinking that promises to surrender can be obligatory only because there are general obligations not to deceive others. But those general obligations do not exist in times of war, according to Deigh, and so they cannot explain why a promise to surrender would be obligatory.
This is going to be rough. I will fill it in later tonight, but right now I have a small person who needs to go to the park.
Remember to start reading at 490! That does not cut out a lot, but it will help.
You can break the reading down into three parts.
Deigh gives his understanding of Hume’s theory of promises, with specific application to how surrendering in war works (490-96). One thing to take note of is his discussion of bad conventions on pp. 491-92, that is, conventions that do not promote the general welfare. Could we use this to address Abby’s question about the convention of treating people as property?
Deigh argues that Scanlon’s principle F cannot apply during war time (496-502). There are two forks here. First, he says that it does not apply because surrender agreements are coerced and so they fail the first clause of Principle F. This limits the principle to voluntary actions that give others assurance of how one will behave. Since “I surrender” would not be voluntary, Principle F would not apply. On the second fork, Deigh considers how Scanlon might make Principle F apply by relaxing the requirement that saying something like “I surrender” has to be voluntary. If we applied Principle F to war in this way, we would get the implausible result that armies are not allowed to deceive one another. So that seems like another dead end.
Finally, Deigh considers the possibility that Scanlon could try to “screen off wartime obligations from obligations made in civilized society” (502). The idea, as I understand it, is to develop a special version of Principle F to apply only to wartime promises like surrender agreements. (I have to confess that I am not entirely sure what he has in mind.) Deigh argues that there is a basic problem with Scanlon’s approach, namely, he has things backwards. Scanlon’s way of handling promises goes like this: “giving the other side assurance about what you will do explains why you are obliged to do that thing.” Deigh thinks it goes like this: “your having the obligation, by invoking the convention, is what gives others assurance.” In order to make this point, he discusses the circularity objection that we ended with last time.