Chris queries my statement that 'discussion and debate are good; we learn through considering different points of view, including those to which we are opposed'. In support of his scepticism he deploys a 1979 study purporting to show that exposing people of different outlooks to arguments and evidence pertaining to what they think tended to polarize rather than narrow disagreements.
I suppose I could, as confirmation of the validity of this conclusion, simply reaffirm my stated view that discussion and debate are good, that we learn from them, and so on, shout it a lot louder and say something rude to or about Chris. But I don't think I'll do that. What I'll do instead is to question the general validity of the study's conclusions as he reports them; question, in particular, whether they can be extended without further research from the reactions of one set of supporters and opponents of capital punishment to the life and trajectory of entire societies. What is the historical evidence regarding degrees and rates of (broadly speaking) learning as between societies that do permit open debate and discussion and societies that do not? OK, I haven't done the research myself, but let's just say one forms an impression about these things. Societies that are free and open about what may be believed, that accommodate unrestricted discussion, appear to do rather better in just about everything than those set about by taboos, restrictions, unfreedoms. This is not only my impression, it is also Chris's own, as he goes on to make clear in due course, referring to the progress that has been due to 'long periods of free expression'.
Yet Chris goes on to say that he suspects (this without further explanation) that 'Mill's consequentialist argument for free speech is weak'. Fair enough. I'll just say, then, that I suspect the opposite - for the reasons alluded to in the previous paragraph.
The two of us do agree on something, however: namely, that there are good non-consequentialist grounds for being in favour of free speech. Yes, it's a fundamental human right not to be in anyone else's power regarding what you may or may not believe. Still, that doesn't mean that the consequentialist argument for free speech should be set aside lightly.