Truth is standardly considered a requirement on epistemic acceptability. But science and philosophy deploy models, idealizations and thought experiments that prescind from truth to achieve other cognitive ends. I argue that such felicitous falsehoods function as cognitively useful fictions. They are cognitively useful because they exemplify and afford epistemic access to features they share with the relevant facts. They are falsehoods in that they diverge from the facts. Nonetheless, they are true enough to serve their epistemic purposes. Theories that contain (...) them have testable consequences, hence are factually defeasible. (shrink)

Instead of conceiving ethical commands as divine revelations or as the discoveries of brilliant thinkers, we should see our ethical practices as evolving over tens of thousands of years, as members of our species have worked out how to live together and prosper. Here, Kitcher elaborates his radical vision of this millennia-long ethical project.