I could imagine someone wanting to swap (1) for another premise. One might say that I have a duty to a person to perform an action when that person can reasonably complain if I do not perform the action. That person can discharge me from my duty to him, as long as he consents, in which case he is ceding his 'right' to complain in the event of non-performance. If I had a duty to myself, though, it would be discharged whenever I consented to its discharging, that is, whenever I want it to be. So it has no normative purchase on me.

iwpoe wrote:

Would that require that moral duties are generally on the model of a contract? Or only some of them?

Yes. I was thinking of this specifically as a contractualist position.

The view that one cannot act unjustly toward oneself, though, goes back to Aristotle. In Nicomachean Ethics V.6, he writes that "there can be no injustice in the unqualified sense towards thing that are one's own" and "no one chooses to hurt himself (for which reason there can be no injustice towards oneself)" (1134b8-13). One wonders how sound the latter inference is, since it seems that people do choose to hurt themselves.

It would obviously be all too quick to lump Aristotle in with the contractualists, though. The view that there are no self-duties is more radical if one thinks that all of ethics is about duty, or that we can concern ourselves and only can concern ourselves with others' fulfillment of their duties, etc. It is less radical in an Aristotelian than in a Kantian. (Kant himself, though, does think self-duty is possible, for one must also respect humanity in oneself.)

iwpoe wrote:

Is that plausible? Would it make them arbitrary or would there be something grounding them?

I am inclined to think it would, though contractualists will have strategies to deny this.

Yeah, so I reviewed the section in Aristotle, and it is quite puzzling.passage. The qualification "there can be no injustice in the unqualified sense (my translation has "in its simple sense")" I think might make the difference. In the Ethics justice in its proper sense is (as Joe Sachs glosses it) "the active condition of the soul by which one chooses neither more nor less than one's fair share of those goods that one can have only by depriving others of them".

The things that are your own are such that you cannot take more or less than your fair share of them (because you already have them). However, justice in its simple sense isn't all of virtue. Aristotle also discusses justice in a broad sense which is, from a certain perspective, all of virtue as it relates to others, but I don't think he's talking about this in the given quote, and even if he is, it's still merely virtue as seen from the perspective of its relation to others.

Joe Sachs intriguingly suggests the following about justice in Aristotle:

"The heavily mathematical treatment of justice up to this point omits any reference to the beautiful, which was said to be the end and aim of all virtue of character (1115b 12-13, 1122b 6-7). This suggests that justice is in some way an incomplete, or undeveloped, virtue, and this will be confirmed in the discussion of friendship in Bks. VII and IX. The active condition of the soul that is necessary and sufficient to make shared life possible may not raise the life that is shared to the form that most fulfills human capacities. Justice may be a necessary step towards that higher condition. And injustice is not merely a matter of the quantity of wrong in an act, but a condition in the soul that determines deliberate choice..."

It may be open to an Aristotelian to say that you have "duties" to yourself in that you fail to perfect your own capacities if you act or fail to act in such-and-such a manner. This wouldn't be an injustice in the simple sense, since you're trivially not excluding an unfair share of something from others in mistreating yourself, but it would still be a failure with respect to eudaimonea.