Here's a cluster of very basic questions those would subscribe to a CT theory need to answer before they can be taken seriously. The plausibility of the answers proffered will set how seriously we can take such persons:
What do you know about structural engineering that structural engineers don't? What do you know about how the federal government functions and how this functionality could make a 9/11 conspiracy viable that political scientists, historians, and those who work for the federal government don't? How did you come to acquire this knowledge?
How has every single conspirator remained silent on the matter, despite the hundreds that would have been necessarily and the inability of the Bush Administration to keep a lid on literally everything occurring under its auspices? Why did Al Qaeda act exactly as if it had carried out the attacks -- its operatives confessing to the operation, its leader declaring it a success, its insistence on carrying out similar such attacks, and its being virtually exterminated in response -- if they in fact did not? How did you come to acquire this knowledge?
Thanks in advance