Today, Pres. Obama signed 23 Executive Orders aimed at curbing gun violence in this country. In his speech about these orders, he talked once again about the reasonable idea of finding reasonable limits on our rights — even our most dearly held rights. And, he uses one of the oldest clichés in the book — we all understand that, as important as free speech is in this country, we still aren't allowed to shout "fire!" in a crowded theater.
I'd like to suggest that using that example actually does a disservice to the point. Because, that one example is fairly extreme and, maybe just as importantly, it's used so often that it becomes the canonical, and seemingly only, example. So, the argument implicitly becomes, "We will accept rare restrictions on our fundamental rights when absolutely necessary." But, if you look at free speech you'll see that we actually accept quite a wide range of restrictions on those rights, for reasons which are far less than existential.
Slander and libel laws tell me what I can and can't say about other people in public. Copyright laws dictate that I can't say something if someone else has said it before. Obscenity laws limit my free speech simply because someone might be offended by it. Truth-in-advertising laws-- doesn't the First Amendment give me the right to claim that my snake-oil will cure your all of your ills? Cyber-stalking and bullying laws. And so on.
I'd argue that the First Amendment is actually more fundamental to American society than the Second — I can imagine a free society functioning without guns, but I can't imagine one without free speech. But, even with that, I accept that the society of which we dream can't really exist without lots of restrictions on that fundamental right.
The language of the First Amendment is absolute, without the confusing (poorly written) ambiguity of the second: "Congress shall make no law...abridging the freedom of speech." No room for debate there. But, still, despite that clarity, we ignore the plain meaning of the text and enact exactly the types of laws that the First Amendment prohibits. We do so because, as fundamentally important as the First Amendment is, it isn't our only value. It isn't our God. It's an incredibly useful ideal, intended to push us towards a better society. But one which, taken to the extreme, becomes destructive. So, we limit it.
That sounds eminently reasonable to me.