Joshua Greene

Joshua Greene is an American cognitive neuroscientist and philosopher known for using neuroimaging to study the neural basis of moral reasoning. His 2013 book Moral Tribes argues that the deepest moral conflicts — between competing moral communities, not merely within them — are coordination problems that cannot be solved by any single group's intuitions.

Greene's experimental work, conducted with Jonathan Cohen and others at Harvard, used fMRI to demonstrate that personal moral dilemmas (e.g., pushing someone to save five others) activate brain regions associated with emotional aversion, while structurally equivalent impersonal dilemmas (e.g., diverting a trolley) do not. This finding was interpreted as evidence for a dual-process architecture in moral judgment: a fast, emotional System 1 that resists harm up close, and a slower, utilitarian System 2 that calculates aggregate outcomes.

The philosophical significance of Greene's work lies in its challenge to moral intuitionism. If moral intuitions are generated by emotionally loaded cognitive subsystems shaped by evolutionary pressures irrelevant to modern dilemmas, then intuitive judgments may be systematically unreliable guides to what we ought to do. Greene's deep pragmatism proposes that moral reasoning should be reconstructed as an explicitly deliberative process that overrides intuition when stakes are high and communities conflict.