Recent controversies about the teaching of creationism in public schools has made me question the limits of free speech.

Like a good scientist, I try to be realistic about the limits of my knowledge, and open to novel ideas.

The problem is people demanding a forum in which to misinform or bias the public about subjects in which the public doesn’t have expertise. This is an exploitation of the openness of free speech and of the humility of science. You can’t “put both sides out there and let people make up their own mind” because falsehoods are often easier to communicate than the truth, and it is sometimes easier to question the truth than to understand it.

Other recent events are making me wonder how free speech might be limited to prevent such exploitation:

• People are attempting to exploit questions about the theory of evolution to promote creationism, under the rubric of "intelligent design"

• People are suggesting that the Armenian tragedy was not genocide.

• People are suggesting that the holocaust did not occur.

• The CPB was monitoring "balance of coverage".