Are you obliged to act like a better person would?
The structure of virtue-ethical theories is often explained like the following: the right thing to do in a given situation is what the virtuous person would do. However, this use of "right" may be deceptive. In analytic ethics we often assume that a person has a moral obligation to do the morally right thing in a given situation. In fact, "having a moral obligation" is widely used synonymously with "morally should." But virtue theories need not make these identifications. At a basic level it is easy to see why: that a different (better) person would do something does not conceptually entail that I should do it.
Moral obligation is a system of the general regulation of behavior -- it characteristically applies to everyone whether their characters are well or poorly constituted. But a person who is poorly constituted -- who is lacking virtue -- cannot simply be fixed by "shoulds." According to Williams, prototypical virtue theorist Aristotle tries to have it both ways on this:
One becomes virtuous or fails to do so only through habituation. One should not study moral philosophy until middle age, Aristotle believes, for a reason that is itself an expression of the present difficulties -- only by then is a person good at practical deliberation. But by then it will be a long time since one became, in relation to this deliberation, preemptively good or irrecoverably bad. (Williams 2006, Ethics and the Limits of Philosophy, 39)
If virtue is a matter of a person's formation, then moral obligation in the direction of virtuous action will sometimes come along too late. The point of moral obligation presumably is the role it is meant to play in practical deliberation -- to guide it towards the good. But if doing this would require reversing a lifetime of habituation, it seems like moral obligation might not be up to the task. And then it can seem pointless and even cruel.
It would be premature to say that there is no role for moral obligation in a virtue theory. But perhaps we can draw a commonsensical distinction: there is in general no moral obligation to behave as though you are a more virtuously constituted person than you really are. Moral obligation must also rest on some other ground.
I previously wrote about the provocative argument that it is wrong to eat fake meat (from this paper). This argument in fact has just the form I have been discussing. There is a virtue of reverence toward (among other things) the vital interests of fellow creatures (490). Enjoying fake meat is so like enjoying real meat that it is incompatible with such reverence.
[T]he consumption of fake meat could be seen as a failure to be reverent towards the suffering and deaths of billions of animals who are used to make real meat. (495)
A virtuous person would exhibit reverence by not enjoying fake meat. Thus, enjoying fake meat is "morally problematic." However, as I have suggested above, an act can be morally problematic in this sense, without necessitating the further conclusion that you have a moral obligation not to do it. Further questions would have to be asked. For example, does the institution of a moral obligation tend to develop the virtue of reverence in a character lacking it, in the given social context? Does whatever benefit there is of instituting such an obligation outweigh the costs of turning the weapon of moral rigor on ourselves? Are better remedies available?