BRUNO LEONI, JAMES M. BUCHANAN, AND THE QUEST FOR A THEORY OF COLLECTIVE ACTION

The essay offers a comparison of the political theories of Bruno Leoni and James M. Buchanan. The focus of the discussion is on the writings of the 1950s and early 1960s, in which both thinkers engage in the elaboration of a theory of collective action. After an initial section (§1) in which the history of the most important collaborations between the two thinkers is reconstructed, the discussion unfolds in three stages. In the first (§2) it is shown that, even before they met, Buchanan and Leoni had developed an identical individualistic conception of the social sciences. This is observed in detail by comparing two essays in which they both deal with the science of finance. Second, (§3) notes how two divergent views of politics emerge from this agreement. Although both focus on the differences between the market and democracy, Buchanan does not believe, as Leoni does, that politics is based exclusively on power asymmetries. This rift seems to be recomposed when Leoni, commenting on the first draft of The Calculus of Consent elaborates his own theory of power exchange. However, it will be shown (§4) that even with this modification the distance between Leoni and Buchanan remains, mainly due to the latter's adherence to the contractualist paradigm, which is unacceptable to Leonian evolutionism.