Hi Derek,

Actually, on reflection, I can see an argument for investigating whether the amoralist can be argued into some moral system, with no restrictions on which system.

Let us define an amoralist as a person who does not believe in any moral system and whose behaviour is not guided by any moral system. If there is no moral system that an amoralist can be argued into - such that for them to reject the argument would be irrational - it may well be concluded that all moral systems are unjustified. This conclusion is an important philosophical result. And so someone might defend the problem of the amoralist, when interpreted as a task of arguing the amoralist into some moral system, any system will do. Considering this problem is worthwhile for evaluating whether all moral systems are unjustified, they will say.

One might try to solve the problem or one might reject the problem as actually a pseudo-problem, by identifying a false commitment of it. So far I do not think we have achieved an adequate case for pursuing the second option, despite this interpretation of the problem looking dubious at first sight.
Terence