I have spent years on this question and I am fairly certain now that Mises’ work, like Bridgman’s was an unsuccessful attempt at developing operationalism.
Both Mises and Popper can best be understood as cosmopolitan intellectuals bringing their pseudoscientific allegorical culture to their work, just as Kant brought continental duty and authority to his – both rebelling against anglo empiricism.
Hayek could not solve the problem of the social sciences either. He correctly intuits that the problem exists, but he can only offer us laments, criticisms, and classical liberal solutions. Unfortunately he did not have decades of computer science to provide him with an alternative conceptual framework and terminology to replace his classical liberalism and moral psychology.
Post mainstream economists cannot yet solve the relationship between mathematics, logic, ethics and economics. And Austrians should have. But the sad state of our ranks and the distraction of philosophers by the marxist, socialist, and postmodern programs misallocated intellectual capital in pursuit of the impossible. So when hayek says the 20th century will be remembered as an era of reemergent mysticism, he only knows something is wrong : endemic pseudoscience – but he does not know why or how to fix it.
He was a herald and a critic but he did not solve it. So did Poincare, Mandelbrot, Bridgman, the mathematical Intuitionists. So did mises.
The interesting insight that I have only recently understood, is that the other disciplines succeeded but their scope was narrower than that of economics. And had mises not failed. Had popper not failed. Had Hayek not failed, then the missing argument would have been available to the less complicated fields of math, logic and science, as well as economics.
The insight that the only truth that can exist is performative, and the only possible claim to sufficient knowledge necessary to make a truth claim, is the demonstration if construction by operational means and measures. Ie: the problem is ethical.
I am fairly certain now, that I have solved that mussing bit -by accident. And that the necessary insights exist in the multiple attempts at articulating operationalism in multiple fields – thereby solving, finally, the nature and definition of truth.
This allows us to repair praxeology as an empirical research program whose theoretical constructs are reducible to operational statements, each of which is sympathetically testable by human perception, as to the rationality and volition of those statements. Ie: truth.
Mises was too much on a mission, too arrogant, too culturally biased, and too ignorant of mathematics, science and philosophy to solve the problem. But he came closer than anyone else had to date.