A point to bear in mind..
Part of the reason it is not a simple answer as to how we determine the content of OM is because the content will depend on the theory of how it is that morality is objective that we are advocating – Moral realism isn’t a single position it’s a plurality of positions in exactly the same way as anti-realism is. So for example if I said to an anti-realist ‘how do we make decide what is right or wrong?’ an individual subjectivist, a societal relativist, a basic principle relativist, etc would all give different answers…
So too with moral realism. If someone thought for example that moral truth was grounded in a form of traditional divine command theory they would say objective morality is based on Gods commands which has presumably been revealed to us in specific definite ways if you hold to a literalist interpretation of Christianity or Islam or whatever.
If you thought that moral realism was grounded in our implicit assumptions within a shared human sensibility then your method would not be to read off truth but rather to draw out what lies behind moral disagreement and then (slowly) tease out how we would react if things were slightly different in order to edge towards consensus.
If you thought that moral truth was grounded in certain core virtues that underpin rational discourse and therefore need to be implicitly embraced by anyone who accepts the practice of ethics then you would have to articulate why these virtues were implicit in rational discourse and draw out how they should be applied in a moral situation.
Etc. Etc. for the record my own view is none of the above although all of the above have been advocated by various types of moral realists. Importantly though agreement on a method doesn’t wipe out moral disagreement – People who agree on virtues that underpin rational discourse for example might disagree for a range of reasons while accepting the same methodology, e.g.
- Disagree on facts, e.g. on extent of suffering caused to animals in modern farming or impact fracking will have on peoples wellbeing balanced against its benefits,..
- Disagree due to interest and emotions/defence of vested positions which distort weight place on arguments beyond what rationally entails
- People talking past one another through different understandings of issue.
All of these are causes of disagreement that mesh together in complex ways, particularly in relation to human societies were moral issues are usually located, that can lead to disagreement in morality even if it was a matter of moral facts – indeed all of these lead to disagreements in science and social science about things that are undisputedly factual too.
So yes moral realists can articulate a way that we progress towards moral truth, depending on the version of moral realism they advocate but this doesn’t make it formulaic or able to simply arrive at undisputed conclusions in most cases.
Regards
DT