Once, when I was holding forth upon the Way, I remarked upon how most organized belief systems exist to flee from doubt. A listener replied to me that the Jesuits must be immune from this criticism, because they practice organized doubt: their novices, he said, are told to doubt Christianity; doubt the existence of God; doubt if their calling is real; doubt that they are suitable for perpetual vows of chastity and poverty. And I said: Ah, but they’re supposed to overcome these doubts, right? He said: No, they are to doubt that perhaps their doubts may grow and become stronger.

Googling failed to confirm or refute these allegations. But I find this scenario fascinating, worthy of discussion, regardless of whether it is true or false of Jesuits. If the Jesuits practiced deliberate doubt, as described above, would they therefore be virtuous as rationalists?

I think I have to concede that the Jesuits, in the (possibly hypothetical) scenario above, would not properly be described as “fleeing from doubt.” But the (possibly hypothetical) conduct still strikes me as highly suspicious. To a truly virtuous rationalist, doubt should not be scary. The conduct described above sounds to me like a program of desensitization for something very scary, like exposing an arachnophobe to spiders under carefully controlled conditions.

But even so, they are encouraging their novices to doubt—right? Does it matter if their reasons are flawed? Is this not still a worthy deed unto a rationalist?

All curiosity seeks to annihilate itself; there is no curiosity that does not want an answer. But if you obtain an answer, if you satisfy your curiosity, then the glorious mystery will no longer be mysterious.

In the same way, every doubt exists in order to annihilate some particular belief. If a doubt fails to destroy its target, the doubt has died unfulfilled—but that is still a resolution, an ending, albeit a sadder one. A doubt that neither destroys itself nor destroys its target might as well have never existed at all. It is the resolution of doubts, not the mere act of doubting, which drives the ratchet of rationality forward.

Every improvement is a change, but not every change is an improvement. Every rationalist doubts, but not all doubts are rational. Wearing doubts doesn’t make you a rationalist any more than wearing a white medical lab coat makes you a doctor.

A rational doubt comes into existence for a specific reason—you have some specific justification to suspect the belief is wrong. This reason, in turn, implies an avenue of investigation which will either destroy the targeted belief or destroy the doubt. This holds even for highly abstract doubts, like: “I wonder if there might be a simpler hypothesis which also explains this data.” In this case you investigate by trying to think of simpler hypotheses. As this search continues longer and longer without fruit, you will think it less and less likely that the next increment of computation will be the one to succeed. Eventually the cost of searching will exceed the expected benefit, and you’ll stop searching. At which point you can no longer claim to be usefully doubting. A doubt that is not investigated might as well not exist. Every doubt exists to destroy itself, one way or the other. An unresolved doubt is a null-op; it does not turn the wheel, neither forward nor back.

If you really believe a religion (and don’t just believe in it), then why would you tell your novices to consider doubts that must die unfulfilled? It would be like telling physics students to agonize over whether the twentieth-century revolution might have been a mistake, and that Newtonian mechanics was correct all along. If you don’t really doubt something, why would you pretend that you do?

Because we all want to be seen as rational—and doubting is widely believed to be a virtue of a rationalist. But it is not widely understood that you need a particular reason to doubt, or that an unresolved doubt is a null-op. Instead people think it’s about modesty, a submissive demeanor, maintaining the tribal status hierarchy—almost exactly the same problem as with humility, on which I have previously written. Making a great public display of doubt to convince yourself that you are a rationalist will do around as much good as wearing a lab coat.

To avoid merely professing doubts,1 remember: