Vienna indeterminism: Mach, Boltzmann, Exner

The present paper studies a specific way of addressing the question whether the laws involving the basic constituents of nature are statistical. While most German physicists, above all Planck, treated the issues of determinis m and causality within a Kantian framework, the tradition which I call Vien na Indeterminism began from Mach's reinterpretation of causality as functio nal dependence. This severed the bond between causality and realism because one could no longer avail oneself of a priori categories as a criterion fo r empirical reality. Hence, an independent reality criterion had to be soug ht, a problem which all three physicists to be studied solved in different ways that were mainly conditioned by their different concepts of probabilit y. In order to prevent a dissipation of intuited facts, Mach had to resort to a principle of unique determination as his reality criterion, especially when discussing the Principle of Least Action. Giving theories more indepe ndence, Boltzmann understood atomism as property reduction to precisely def ined theoretical entities and their interactions. While this served as a re lative reality criterion, he also advocated a constructivist one because at omism was already implied by our finitary reasoning power. Finally, Exner c ontemplated the idea that all apparently deterministic laws are only a macr oscopic limit of an irreducible indeterminism, because by adopting the freq uency interpretation, observable collectives could be considered as the rea l basic entities.