ABSTRACT

Moral intuitions are being drawn out of people in the lab, on websites, and in brain scanners, and are being explained with tools from game theory, neuroscience, and evolutionary biology. The human moral sense turns out to be an organ of considerable complexity, with quirks that reflect its evolutionary history and neurobiological foundations. Many of these moralizations, such as the assault on smoking, may be understood as practical tactics to reduce some recently identified harm. People don't engage in moral reasoning, Haidt argues, but moral rationalization: they begin with the conclusion coughed up by an unconscious emotion, and then work backward to a plausible justification. The institutions of modernity often question and experiment with the way activities are assigned to moral spheres. Market economies tend to put everything up for sale. The science of the moral sense alerts us to ways in which our psychological makeup can get in the way of our arriving at the most defensible moral conclusions.