I was doing a cursory skim of George Reisman's Capitalism to see what kind of book it is before diving in. It's available in PDF for free download at Mises.org. One thing stood out and it's sort of a pet peeve of mine about Austrian economists is a dismissal of mathematical economics, but George said it so well that I didn't mind:
"Another prominent school of economic thought is that
of mathematical economics, which is characterized by
the use of calculus and simultaneous differential equations to describe economic phenomena. The principal
founder of mathematical economics was Léon Walras
(1834–1910), a Swiss, who also independently discovered the law of diminishing marginal utility shortly after
Menger and Jevons. Vilfredo Pareto (1848–1923), an
Italian, succeeded Walras at the University of Lausanne
and elaborated his approach.
Mathematical economics is fundamentally a matter
more of method and pedagogy than of particular theoretical content. And although neither the classical nor the
Austrian schools is mathematical in the above sense,
there are mathematical economists who are allied with
their teachings and their support of capitalism. Walras,
Jevons, and Gossen are important cases in point.
Regrettably, the use of calculus and differential equations to describe economic phenomena represents a
Procrustean bed, into which the discrete, discontinuous phenomena of actual economic life are mentally forced, in
order to fit the mold of mathematically continuous functions to which the methods of calculus can be applied.
This has consequences which represent a matter of theoretical content, as well as method."
This point is important and it is also brought up by Nicholas Nassim Taleb in his Incerto series. How much can we trust the continuity of mathematical functions in modern economics?