Existential Quantifiers and Guiding Principles in Physical Theories

Abstract

In the 1969 Postscript to the second edition of The Structure of Scientific Revolutions. Thomas Kuhn set out to reply to several objections that had been made against the first edition of the book (1962). Among those objections there was one that Kuhn took most seriously. It was the claim that his famous notion of a “paradign,” as a structure underlying the whole of a discipline during a period of normal science was irremediably vague and ambiguous. Kuhn tried to make the notion more precise, and for this reason he even changed the terminology: The “paradigm”of the first edition became the “disciplinary matrix” of the Postscript. It seems that the new term has had no good fortune; people continue to talk about “paradigns” and, even worse, they continue to talk about them with the same vagueness which characterized Kuhn’s discussion in the first edition of his work. Of course, the issue at stake is not merely terminological, and therefore we can go on using the term “paradigm” instead of “disciplinary matrix” in the present context. What really matters is that Kuhn tried to make the structure of his basic notion more precise and for this reason he identified four components that, in his view, are essential to a paradigm: symbolic generalizations, ontological and heuristic models, methodological values, and “paradigmatic” exemplars of applications. Shortly afterwards, in Structures and Dynamics of Theories, Stegmuller used the formal apparatus of Sneed’s Logical Structure of Mathematical Physics to formalize the notions involved in the first and last components identified by Kuhn in a paradigm. According to Stegnuller, Kuhn’s “symbolic generalizations” are nothing but the fundamental laws of a theory’s so called “structure core.”

The original Spanish version of this essay appeared in Crítica 29 (1978). I translated it into English without introducing any essential changes. I wish to thank Prof. William Craig (Berkeley) and my friend, Ignacio Jane (Mexico) for their suggestions and criticisms. Of course, I am the only one responsible for the mistakes that might still be present.