A few points:
The standard explanation is, and should be the default explanation: given that we know that there were planes that crashed into the towers, we know that OBL had "declared war on" and attacked the US previously, that the attackers had previous ties to Al-Qaeda, among their other extremely well known and studied background info, etc, we have more than enough info to establish that there was in fact a successful Al-Qaeda plot to attack the WTC, in essentially the known manner.
So the conspiracy theorists are starting with exceedingly weak priors for their case; they also have no persuasive/effective evidence in their case's favor. I don't really feel any need to list every possible argument against the standard case and their flaws, but see eg here or here.
the conspiracy theorists are starting with exceedingly weak priors for their case
The priors are exceedingly week because the evidence in your comment is filtered. You did not mention e.g. this: War is an excuse to tax citizens and buy weapons from big producers, who in turn sponsor politicians -- therefore politicians have an incentive to declare wars to keep the money flowing. Also war helps to turn attention away from domestic problems. Or this: False flag operations are sometimes used to start a war.
Even including this, it may still result that WTC attacks most probably happened similarly to the official version. But making your case seem stronger than it really is, is still a sin against rationality.
Yes, but as I said, there's absolutely no evidence whatsoever that there was a government conspiracy, whereas the al-Qaeda plot has been exceedingly well documented; there's no reason to believe that government officials had a motive, whereas Osama had repeatedly stated that he would attack the US, and had done so previously. More specifically:
Remember, Bush explicitly wanted to focus on domestic policy, promised a humble foreign policy, with no nationbuilding, and criticized Clinton/Gore for running too interventionist foreign policy. It's only hindsight bias that makes us think that Bush wanted a war. It's true that Bush later changed his policy. But he wouldn't claim that he opposed war during his campaign, when he'd need donations, and then support it during his presidency, when public/congressional support mattered more.
Similarly, there honestly weren't any particularly large problems Bush needed to distract the public from; polling showed that he had 55% approval, and just 41% disapproval; this had been fairly steady, and, as a comparison, was higher than Obama's at the same point in his presidency, even though Obama won by a much larger margin.
Finally, that vastly underestimates the difficulty of keeping false-flag operations secret.
One last point is that I may have confused you about what I'm calling "priors"; I'm referring solely to the priors for the claims rysade brought up, regarding the actual mechanics of the destruction, which include the stuff I brought up in my first section above as evidence. I agree that the priors for any terrorist attack in the US being a false flag operation are somewhat higher than the posteriors given the above evidence- thus the fact that I posted the above evidence.
From my experience, conspiracy theorists are like everyone else epistemologically except they have different motivations: most people want to believe the world is just, while conspiracy theorists want to believe the world is sinister. Like with most people, you have to watch out for motivated skepticism or what skeptics call anomaly hunting.
To guard against that, you'll have to find a way to make their evidence clearly defined and inescapable. I recommend having them write down all the evidence for their belief that 9/11 was blah blah and then weight it. Here's an example:
Ask them what percentage of that evidence is sufficient for their belief, and then just take the paper and research it. Come back another day and discuss your findings dialectically.
If you're looking for information resources, here's some mixed quality ones from my bookmarks:
I suppose if you really wanted to get into it, you could go read an engineering review of what happened.
I hope I'm not breaking any taboos here. It's been a while since I've come onto the discussion section and I admit I'm not too up to date on the topics.
I'm having difficulty responding to someone who is convinced that 7WTC was brought down by controlled demolition on September 11th, 2001. They're referencing the controlled-looking destruction of 7WTC and various other incriminating looking things. Thermite and thermite waste products seem to come up a lot.
Now, I have definitely noticed I'm confused here. While I hold the opinion that the towers went down because of the planes/fires (i.e. the standard explanation) I have difficulty seeing how the falsity of controlled demolition is the slam-dunk folks seem to think it is. Could somebody walk me through this?
[EDIT: About a million edits later, I have finally worked through the problem with my link: I needed it to be in HTML and not in the comment format.]