Oppenheimer started out as a physician. Then he studied economics and wrote his PhD dissertation on David Ricardo. After accepting a call to serve as Chair for Sociology and Theoretical Political Economy at Johann Wolfgang Goethe University in Frankfurt/Main (the first chair dedicated to Sociology in Germany) a cooperative agricultural community of individual farms (called a "Moshav") was founded by Jews using Oppenheimer's blueprint. Oppenheimer later taught in Palestine. He fled Nazi persecution to Los Angeles, and became a founding member of The American Journal of Economics and Sociology.
Oppenheimer's book The State looks at the origins of this political entity:
"The State, completely in its genesis, essentially and almost completely during the first stages of its existence, is a social institution, forced by a victorious group of men on a defeated group, with the sole purpose of regulating the dominion of the victorious group over the vanquished, and securing itself against revolt from within and attacks from abroad. Teleologically, this dominion had no other purpose than the economic exploitation of the vanquished by the victors."Economic Man and Political Man
"No primitive state known to history originated in any other manner. Wherever a reliable tradition reports otherwise, either it concerns the amalgamation of two fully developed primitive states into one body of more complete organisation, or else it is an adaptation to men of the fable of the sheep which made a bear their king in order to be protected against the wolf. But even in this latter case, the form and content of the State became precisely the same as in those states where nothing intervened, and which became immediately 'wolf states'." (p. 15)
Oppenheimer made the compelling observation:
"There are two fundamentally opposed means whereby man, requiring sustenance, is impelled to obtain the necessary means for satisfying his desires. These are work and robbery, one's own labor and the forcible appropriation of the labor of others. Robbery! Forcible appropriation! These words convey to us ideas of crime and the penitentiary, since we are the contemporaries of a developed civilization, specifically based on the inviolability of property. And this tang is not lost when we are convinced that land and sea robbery is the primitive relation of life, just as the warrior's trade - which also for a long time is only organized mass robbery - constitutes the most respected of occupations. Both because of this, and also on account of the need of having, in the further development of this study, terse, clear, sharply opposing terms for these very important contrasts, I propose in the following discussion to call one's own labor and the equivalent exchange of one's own labor for the labor of others, the “economic means" for the satisfaction of needs, while the unrequited appropriation of the labor of others will be called the "political means." (pp. 24-25)Albert Jay Nock introduced these concepts to American readers in his own book Our Enemy, the State.
h/t Wikipedia