I've been thinking about Edward Feser's conservative take on conspiracy theories: that they are really a case of the Enlightenment spirit taken to its logical limit, with the individualistic "theorist" rejecting tradition and authority in favor of the judgement of his (it always is a "he") own mind. It's an application, he says, of the "skim milk principle," so named after the Sir Arthur Sullivan lines "Things are seldom what they seem/Skim milk maskerades as cream."
I should probably point out first of all that my own account and Feser's have something in common. They are both basically epistemological accounts of cospiracism. That is, they both interpret it as a knowledge claim and assess it in terms of whether its methodology is competent to (or seriously meant to) support claims to knowledge.
However, within the wide parameters of epistemological accounts of conspiracism, my view is virtually opposite of Feser's. Connspiracy "theories" are not really theories at all. They are, as Plato would say, not logos but mythos, stories that deliver the subjective satisfaction (the drug-like high) of theories without the difficulty, discipline, or rigor of doing actual theoretical work.
As I said below, Feser's account does admittedly explain something that my own account seemingly cannot: namely, that conspiracists tend to be individualists who are "agin the guvmint." I should add something to my account. But what?
I guess what I am inclined to add is a denial that the explanandum phenomenon, the thing to be explained, exists. True, we do think of the typical conspiracist as some weird guy who lives in his mom's garage and has a web site that reveals the key to human history. But that is a sort of illusion of perspective we get by looking only at the conspiracists immediately around us. Step back and look at the big picture.
Historically, conspiracism has often been a very nasty tool in the hands of authority, the worst and most authoritarian authorities. What was Nazi antisemitism but a giant conspiracy theory? Soviet Communism was rife with conspiracy theories. At the time he died (and it was just in time) Stalin was obsessed with The Doctors' Plot, a conspiracy theory that was to have served as the basis for massive arrests and killings. Just the other day, the dictator of Sudan used a conspiracy theory to deny responsibility for mass murder in the Darfur region and blame it all on Israel.
Again, Medieval witchraft hysteria had the most salient traits of conpiracism, inasmuch as it opposed a foe that was a) very powerful, b) very, very bad, and c) invisible (undetectable by ordinary common sense thinking).
Conspiracism is a wonderful excuse for doing terrible things to innocent people. A conspiracy theory would, if true, justify taking extraordinary means against people who look innocent because, don't you know, THEY are about to do terrible things to us, and they are very good at looking innocent. It's what they do!
As a non-conservative, I maintain that beating up on people in just this way is one thing that authority, throughout history, has shown a certain tendency to do. Lord Acton said it: Power corrupts.