According to the working definition of conspiracy theories in â€œShit Happensâ€, it is a necessary condition that the hypothesized conspirators â€œkeep their intentions and actions secret.â€ Since a central point of â€œShit Happensâ€ is that conspiracy theories are universally unwarranted, prima facie warranted conspiracy theories (mainstream explanations involving the individuals involved in Watergate, al Queda, Nazi Germany) need to be addressed.
We can focus the concern that needs to be addressed in terms of a pair of questions. Arenâ€™t we warranted in the common belief that, e.g. al Queda blew up WTC? And isnâ€™t the common belief (e.g. that al Queda blew up WTC) a conspiracy theory?
The strategy I currently find most appealing is to answer the first question positively and the second negatively. The next question that immediately arises is why arenâ€™t these prima facie warranted conspiracy theories really conspiracy theories. My answer is that they fail the necessary condition of keeping secret.
There are several ways in which one can fail to keep secrets. One way is by getting caught and being compelled to testify in a criminal investigation. In this case one may have tried then failed to keep the secret. A related way is when direct evidence (video tape of someone building and planting a bomb) renders the secret no longer kept. Another way of failing to keep secret is illustrated by terrorists broadcasting their involvement in a plot in order to take credit for its success. In this case the sense in which they fail to keep a secret is by no longer even trying to keep it secret.
A true conspiracy theory attempts to leap over a wall of posited secrecy via attempts at inference to the best explanation. The main problems arise in establishing that the proffered explanation is indeed the best instead of swamped by multiple equally plausible explanations. In cases that we are warranted in believing, e.g. that al Queda planned the 9/11 bombings, we arenâ€™t stuck making such a leap.