While there are predictable (and accurate) objections to this quote as such, at heart it's good sense. On the one hand, it can mean the same thing as "the rational thing is the thing that wins", and on the other it can mean something like "if you predict that it has a low probability of working, but it works, then that is evidence that should raise your estimate of its likelihood of working," both of which are, I'd imagine, lesswrong-approved sentiments.