Ludwig von Mises (1881–1973) developed Austrian economics and praxeology. He studied how people choose means to ends and how money prices enable comparison of economic alternatives.
The Theory of Money and Credit appeared in 1912; the article on socialist calculation in 1920. When using later editions, distinguish the original text, a foreword and the publisher’s commentary. [Mises Institute — Ludwig von Mises, biographical profile]
Mises’s concept of action requires neither a correct theory nor a successful result. Someone can choose an unsuitable means while pursuing a goal; purposefulness guarantees neither infallibility nor moral approval of the goal. [Mises — Human Action, II: Praxeology and History]
Mises separates general relationships of action from investigation of particular events. A deduced theorem does not itself supply all historical facts; its assumptions must hold when it is applied. [Mises — Human Action, II: Praxeology and History]
An engineer can calculate quantities of material. Economic calculation also compares money costs and expected proceeds of alternatives; physical units alone do not replace that comparison. [Mises — Human Action, XII: The Sphere of Economic Calculation]
Past prices guide expectations rather than provide certain knowledge of the future. Even a calculation exact to the cent relies on estimates; numerical precision does not guarantee the outcome. [Mises — Human Action, XII: The Sphere of Economic Calculation]
In monetary theory Mises rejects classification solely into metal and paper. He also examines claims and their repayment conditions; do not transplant his historical categories to a present product without explanation. [Mises — The Theory of Money and Credit, I.3.3]
In the Human Action foreword, Mises expressly uses liberal in its classical sense associated with markets and personal freedom. Do not automatically assign him a current party label from another country. [Mises — Human Action, XII: The Sphere of Economic Calculation]
Mises died in 1973; the Mises Institute was founded in 1982. A current Bitcoin article represents its author or institution, not Mises’s own position or investment advice. [Mises Institute — Ludwig von Mises, biographical profile]
For the clearest picture, read this entry together with Praxeology, Human Action, Economic Calculation, Regression Theorem. The reverse links also lead from Austrian economics, Socialist Calculation Debate, Regression Theorem.