Carl Menger (1840–1921) founded the Austrian school of economics with his 1871 work. He developed theories of value, relations between goods and the spontaneous emergence of a medium of exchange.
Carl Menger taught at the University of Vienna and published Grundsätze der Volkswirtschaftslehre in 1871. Do not confuse him with his son Karl Menger, a mathematician; they are different people. [University of Vienna — Carl Menger, archival biography]
In his value theory, what matters is the importance of the satisfaction that depends on having a particular good. Labour spent producing it does not itself determine value; high costs do not guarantee a high valuation. [Menger — Principles of Economics (1871), chapters I and III]
Bread meets a need directly; flour and production tools do so indirectly. Higher order describes a position in a particular production relationship, not a permanent physical property or superior quality. [Menger — Principles of Economics (1871), chapters I and III]
The 1892 article On the Origin of Money distinguishes the purchase price from the price obtainable on resale. Easily saleable does not mean immediately saleable at any price the seller wishes. [Menger — On the Origin of Money (1892), sections IV–IX]
Someone may accept a good they will not consume because it is easier to exchange onward. Menger explains how learning and imitation of successful practices help spread a generally accepted medium of exchange. [Menger — On the Origin of Money (1892), sections IV–IX]
Menger distinguishes money’s origin from subsequent legal recognition and coinage regulation. He also allows for legislation to institute a medium of exchange; his account does not say the state can never play any role. [Menger — On the Origin of Money (1892), sections IV–IX]
The 1883 book Untersuchungen defended theoretical research against the German historical school. Do not automatically equate this particular dispute with every later method employed by Austrian economists. [University of Vienna — Carl Menger, archival biography]
Menger died in 1921. Applying his concepts to today’s Bitcoin debate is a later interpretation, not his own position; always identify who draws the contemporary conclusion. [University of Vienna — Carl Menger, archival biography]
For the clearest picture, read this entry together with Subjective Value Theory, Marginal Utility, Capital Goods, Commodity Money. The reverse links also lead from Austrian economics, Subjective Value Theory, Marginal Utility, Eugen von Böhm-Bawerk.