Every era has its dangerous ideas. For millennia, the monotheistic religions have persecuted countless heresies, together with nuisances from science such as geocentrism, biblical archeology, and the theory of evolution. We can be thankful that the punishments have changed from torture and mutilation to the canceling of grants and the writing of vituperative reviews. But intellectual intimidation, whether by sword or by pen, inevitably shapes the ideas that are taken seriously in a given era, and the rear-view mirror of history presents us with a warning..."Complete essay by Steven Pinker here.
More on the topic at the Freakonomics Blog.