Moral philosophy often makes use of personal perceptions of moral intuitions and durable well-being (or happiness or flourishing) to judge the worth of foundational moral premises such as those underlying Utilitarianism, egoism, and virtue ethics. For John Rawls’ “reflective equilibrium behind a veil of ignorance” theory of justice, imagined moral intuitions from all conceivable perspectives directly determine what is just.
Moral philosophy rightly prides itself on logic and rationality in considering the implications of foundational moral premises. However, the formulation and justifications for foundational moral premises are on shaky ground to the extent they rely on personal perceptions of moral intuitions and durable well-being.
Further, once morality’s ‘ends’ in consequentialist moral philosophies are established, it is often not obvious what moral standards ought to be enforced to best achieve those ends, such as “maximize well-being for the most people”, “maximize personal well-being”, or be in accord with “reflective equilibrium behind a veil of ignorance”.
The above difficulties have hampered moral philosophy since the time of the ancient Greeks.
Moral philosophy’s reliance on personal perceptions of moral intuitions and durable well-being may be ending.
Purely descriptive, objective knowledge from the science of morality is revealing the origins and function of our moral intuitions, cultural moral standards, and experience of durable well-being. Here, the science of morality means morality understood as biological and cultural evolutionary adaptations.
Over the last 35 years or so, it has become progressively clearer that social moralities (morality dealing with interactions with other people) are sets of biological and cultural evolutionary adaptations selected for by the benefits of altruistic cooperation in groups. That means our moral emotions such as empathy, loyalty, and guilt, our moral intuitions, much of our experience of durable well-being, and past and present enforced moral standards were all selected for by the increased benefits of altruistic cooperation in groups they produced.
That purely descriptive science could have profound implications for moral philosophy.
But a standard moral philosophy position has been that purely descriptive science is irrelevant to moral philosophy. After all, “You can’t derive a (moral) ‘ought’ from (what science tells us) ‘is’”. But descriptive science is not telling what we ought to do, only about what objectively ‘is’. While what we ultimately “ought to do” will remain forever outside the domain of science (as I think it logically must), descriptive science may be a highly useful tool for moral philosophy’s deliberations on “How should we live?”
The descriptive science of morality is moral philosophy’s useful servant, not its prescriptive master.
John Bordley Rawls (February 21, 1921 – November 24, 2002)