How do we know all conspiracy theorists are nuts?

I'm gonna get philisophical on you here, so bear with me.

At what point do we stop writing off every nutjob with a theory that sounds more like Saturday morning cartoons than fact? There are a million different theories and ideas out there, and I think it's pretty damn cocky to think that we have a handle on the world (and everything) today.

Everything from the theory of life, the universe, and everything, to 9/11 conspiracies, to the theory of relativity.

Let's start with science. Time and time again we find out that what we "know" as fact is wrong. For instance, once upon a time, we "knew" the world was flat. We "knew" that the Earth was the center of the universe. We "knew" that the Sun was the center of the universe. We "know" that we can't travel faster than the speed of light. We "know" there is a God who watches over us, and loves us, and needs us. Yes, Einstein was probably the smartest man within at least the last 100 years, but what if he was wrong? Is it really so impossible? We know so little about the universe. Is string theory right? Probably not, but some of its fundamental ideas are intriguing. I guess what I'm trying to say is that we don't know. Not only do we not know, but we very well may never know. We go through the motions every day, waiting... hoping... working... for what? for whom? We're so cocky. We're so all-knowing. We're so sure.

NYTimes: Spy Agencies Say Iraq War Worsens Terror Threat

From the article:

A stark assessment of terrorism trends by American intelligence agencies has found that the American invasion and occupation of Iraq has helped spawn a new generation of Islamic radicalism and that the overall terrorist threat has grown since the Sept. 11 attacks.

Time to leave Iraq?

How long till we're out of Iraq? To my knowledge, no one is suggesting we stay in Iraq forever, so this isn't a question of if we're leaving but when. Of course, we went to Iraq for a reason. Victory in Iraq used to mean something: (1) Outsting Saddam, (2) Finding the WMD that were in imminent danger of falling in to terrorist hands, and (3) Helping the Iraqis set up a constitutional democracy - which would, of course, spread freedom and pro-western democracies all over the Near East region. Well, Saddam is gone, there were no WMD (unless you're Crazy Rick "OMG WMDS ARE EVERYWHERE LOL!!11" Santorum), and the government is up but only religious fundamentalism is spreading.