The Genesis of the Uncertainty Principle: A Historical-Epistemological Analysis of the Werner Heisenberg-Wolfgang Pauli Correspondence (1927)

Abstract

This article investigates the historical–epistemological genesis of the Uncertainty Principle through an analysis of the scientific correspondence between Werner Heisenberg and Wolfgang Pauli, with particular emphasis on the long letter dated 23 February 1927, written immediately prior to the publication of the paper in which the principle was formally introduced. In contrast to retrospective narratives that treat uncertainty as a direct consequence of the mathematical formalism of Quantum Mechanics, the study demonstrates that the principle emerged from a gradual process of conceptual elaboration grounded in operational reflections on measurement, the redefinition of the physical meaning of classical quantities, and the role of observation. A close, commented reading of the letter reveals an intermediate stage in which relations of indeterminacy appear as heuristics tied to conditions of measurability, before being discursively stabilized as a general principle in the published article of 1927. The comparison between private correspondence and public exposition makes it possible to identify conceptual continuities, epistemological shifts, and rhetorical strategies associated with the consolidation of the principle. It is argued that the construction of the Uncertainty Principle is best understood as the outcome of a collective and argumentative process, shaped by epistolary exchange, institutional debate, and public controversy, including the discussions at the 1927 Solvay Conference. By foregrounding primary sources, the article contributes to a historically informed understanding of Quantum Mechanics and to a critical reassessment of excessively formalist interpretations of its foundations.