You can’t learn about morality from brain scans. Thomas Nagel’s review of Joshua Greene’s Moral Tribes. Many interesting issues in the review: human rights v. the greatest happiness of the greatest number, trolleyology, moral instinct, and others.

Nagel says of Greene: “Greene wants to persuade us that moral psychology is more fundamental than moral philosophy. Most moral philosophies, he maintains, are misguided attempts to interpret our moral intuitions in particular cases as apprehensions of the truth about how we ought to live and what we ought to do, with the aim of discovering the underlying principles that determine that truth. In fact, Greene believes, all our intuitions are just manifestations of the operation of our dual-process brains, functioning either instinctively or more reflectively. He endorses one moral position, utilitarianism, not as the truth (he professes to be agnostic on whether there is such a thing as moral truth) but rather as a method of evaluation that we can all understand, and that holds out hope of providing a common currency of value less divisive than the morality of individual rights and communal obligations. ‘None of us is truly impartial, but everyone feels the pull of impartiality as a moral ideal.'”

Nagel isn’t so sure and explains why.