Block and Rothbard do not understand Austrian economics and are incapable of defending it against serious rationalist criticism. Ludwig von Mises is the only rigorous rationalist in the "school". His works make mincemeat of Caplan's arguments decades before Caplan even makes them. But don't take my word for it - go back and reread Mises directly.
You will see that the "rationalist" objections Caplan raises are not new. They are simply born out of a misunderstanding of a complex topic. Rothbard, Block, and most of the other "Austrian" economists that followed merely added another layer of confusion because they weren't careful enough thinkers to understand Mises.
ETA: Speaking of Bayesianism, it was also rejected for centuries as being unscientific, for many of the same reasons that Mises's observations have been. In fact, Mises explains exactly why probability is in the mind in his works almost a century ago, and he's not even a mathematician. It is a straightforward application of his Austrian epistemology. I hope that doesn't cause anyone's head to explode.
It's been a while since I read Man, Economy, and State, but it seemed to me that Rothbard (and therefore possibly von Mises) anticipated chaos theory. There was a description of economies chasing perfectly stable supply and demand, but never getting there because circumstances keep changing.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.