[A]re there instances of conspiracy theories that turn out to be correct?
To which I answer a resounding ‘Yes,’ but in three parts.
One: Any explanation of an event that references a Conspiracy is a Conspiracy Theory
This answer is simple; the explanation of the death of Gaius Julius Caesar is a Conspiracy Theory because we know that people conspired against the Dictator and that this Conspiracy was a cause of his death (not the cause, however; that was stabbing (well, ultimately, oxygen starvation of the brain; the stabbing caused that and that caused JC the First to die)). Thus there are lots of examples of Conspiracy Theories being true.
I suspect, however, that what Paul really is asking is whether speculative Conspiracy Theories ever turn out to be true. The death of Caesar is a bad example because the co-conspirators admit to their deed fairly quickly and people aren’t left speculating as to what really happened. Thus I rush through History and enter the 20th Century and say, simply, the Trotsky Trials.
Two: Some speculative Conspiracy Theories are explanations
In the early part of the 20th Century Leon Trotsky (and some friends) were put on trial by the Russian State for treason. The Trials were held in public and a big fuss was made of these being good, honest examples of judicial behaviour. The American and British Governments assured the world that justice was, indeed, being served by our friends in Communism and that all was right with the world. Those freaks at the Dewey Commission, with their claim that the trials were a sham and that it was all for show; that Trotsky’s verdict was pre-arranged and that the evidence was trumped up and largely fabricated were just loons, Conspiracy Theorists, if you will.
Except that the Dewey Commission was right (and not just accidentally; they were right on most of the substantive matters). The Trotksy Trials were a sham. It was, indeed, a Conspiracy to render a guilty verdict on Leon Trotsky and his supporters. The Conspiracy Theory was revealed to be true by the Russian State some twenty years later. This Conspiracy Theory referred to an actual case of Conspiracy and was thus an explanation of the event under consideration.
Which leads me on to my third answer, which is to do with History itself.
Three: Every Historical Explanation is a theory and some Historical Explanations will thus be Conspiracy Theories.
One of the problems with the term ‘theory’ is that it means quite different things according to the context in which it is used. When I say ‘the Theory of General Relativity’ I mean theory in a sense that is quite disimilar to when I say ‘the police’s theory that Sione Te Namu was killed by jackals and not by her girlfriend.’ Historical explanations, similarly, are different to those kinds of explanations you find in the Natural Sciences. Thus speculative Conspiracy Theories can turn out to be good explanations. Indeed, in the past, they have been.
[There is a fourth answer, which would go something like: Of course there are true Conspiracy Theories because we have successful prosecutions of Criminal Conspiracies. However, that is a matter I’m not currently touching upon in my thesis, if only because it does seem to be a different case from the more ‘speculative’ Conspiracy Theories we find in History.]
1. This is a tad contentious in both directions; some people think that Social Scientists have the wrong idea of what explanations should look like and some people think that the Natural Scientists are flogging a dead explanatory horse. That, however, is probably anoher matter for another time.