Before I begin, there is yet another reason for free speech. Allow me to give an example.
I make a habit of discussing and researching firearms and gun politics. It is my belief that gun control advocates are incorrect in general, outright false in several areas, and downright misleading in others.
Yet for all that, you know something? I am imperfect, right? Of course. And that means that I will, from time to time, fall into wrong ideas myself, right? Well, when I espouse an incorrect idea about gun rights, who do you think is the quickest to point it out to me?
Gun control advocates, not gun rights' supporters. Though I believe them to be false, they still serve a CRUCIAL purpose to me!
People naturally pick apart ideas that they disagree with, and tend to blindly accept ideas that they agree with. Notice that we often choose to agree with something before we actually understand it.
Therefore, I will STRENUOUSLY defend the right of gun control advocates to speak out. I will even defend it with guns if necessary.
Yes, you knew that was coming. I did it anyway.
Anyways, that is because
Dissenting opinions in and of themselves are necessary to the progression of society.
They are the primary means by which we learn.