o see how we treat the concept of truth these days, one might think we just don’t care anymore. Politicians pronounce that global warming is a hoax. An alarming number of middle-class parents have stopped giving their children routine vaccinations, on the basis of discredited research. Meanwhile many commentators in the media — and even some in our universities — have all but abandoned their responsibility to set the record straight. (It doesn’t help when scientists occasionally have to retract their own work.)