A rationalistic moral relativist might say that actions require goals, ultimate goals are arbitrary, and so rationality cannot be the starting point there.
Lots of things act without having any sort of goals. Does fire have a goal of reducing high-energy compounds into oxidized components and free energy? No, but it does it anyway.
You can limit ‘action’ to intentional events only, I suppose.
However, how does declaring that goals are arbitrary rule out assertions about necessary starting points?
So it could be countered that ‘rationality’ never has to supply everything; its purpose will largely be to critique existing purposes, order them by significance, or evaluate new possibilities.
If the goals already developed are incompatible with each other, rationality isn’t going to help much. If they’re incompatible with rationality, it really isn’t going to help. But no helping is possible.
Say something more about what you think the role of rationality should be in developing a morality, and about the particular powers it has to fulfil that role.
Rationality is required to form a coherent model (however incomplete or imperfect) of the world. To take an action with the intention of bringing about a specific result requires a coherent model. Ergo...
An incoherent actor can’t be said to have any goals at all.
Lots of things act without having any sort of goals. Does fire have a goal of reducing high-energy compounds into oxidized components and free energy? No, but it does it anyway.
You can limit ‘action’ to intentional events only, I suppose.
However, how does declaring that goals are arbitrary rule out assertions about necessary starting points?
If the goals already developed are incompatible with each other, rationality isn’t going to help much. If they’re incompatible with rationality, it really isn’t going to help. But no helping is possible.
Rationality is required to form a coherent model (however incomplete or imperfect) of the world. To take an action with the intention of bringing about a specific result requires a coherent model. Ergo...
An incoherent actor can’t be said to have any goals at all.