"...that, basically, the importance of having as wide agreement as possible in free speech comes down to the fact that, firstly, you may need to hear opinions you do not want to hear because you yourself may be in error. And if you're not entirely in error, you may at least be partly in error. And you may need to be put back on a good course. And you may not be able to get back on a good course unless you can hear speech which some people may wish to deprive you of.
Secondly, the other defense being that even if the opinion is wrong, it can do you no harm to hear it because in the hearing of it you will know the arguments against your position and in the process will be able to strengthen your own position. You will know better why you are right. You will know better why some things are true and some things are not. And you will be able to have a better armory to your own opinions. I think this has to be borne in mind very carefully because among other things at the moment there are moves across Europe to criminalize speech and criminalize writing which is often filled with error. Let me give you one quick example. The appalling nazi apologist, so-called historian, David Irving. Now some people's responses to him and to his fake scholarship is to criminalize him, to put him in prison, and so on. And I think that's exactly the wrong way to deal with him. The right way to deal with him is to debate him, to have other scholars of equal or, more importantly, greater stature able to pick apart his lies. But if you don't do that, you can be absolutely certain that a few years down the line you will have a generation of people who when they are confronted by an Irving, who has spent many years in archives and knows his 1930s and 1940s handwritten German very well, you can be sure that there will be a time in the future if you have simply criminalized that, locked people in prison, that you will have a generation who says, 'The holocaust happened. Of course it happened' and somebody else comes along and says, 'no it didn't' and the people saying it did are not prepared. 'It happened because we have laws that say it happened. It happened because, well, we know it happened.' But you haven't been able yourself to enforce that argument. You haven't encouraged other people to enforce that argument. And so we become weaker as a society. We become less able to explain our own history. We become less able to explain our own truth."