The Notion of "Functional A Priori" in Arthur Pap's Philosophy of Science

Philosophy of Science Colloquium
The Institute Vienna Circle holds a Philosophy of Science Colloquium with talks by our present fellows.

Date: 16/04/2026

Time: 16h45

Venue: New Institute Building (NIG), Universitätsstraße 7, 1010 Wien, HS 3C

Abstract:

In this talk, I will present Arthur Pap’s contribution to debates about the nature and function of the a priori in scientific knowledge. Arthur Pap was a Swiss philosopher of science of Jewish origin who lived between 1921 and 1959. Like many other European philosophers at that time, he was forced to move to the United States to escape Nazi persecution. There, a multifaceted philosophical environment was emerging, thanks to the interactions between European philosophers of science who had emigrated and their American colleagues. It was in this context that Pap, influenced by logical empiricism, neo-Kantianism, conventionalism, and American pragmatism, developed his functional interpretation of the a priori.

I will outline Pap’s criticism of the rigid dichotomy between analytic a priori and synthetic a posteriori judgments, as postulated by logical empiricists, and his dynamic point of view, in which scientific propositions can change their function and epistemological status at different stages of enquiry. Pap describes a “path towards analyticity”, whereby certain synthetic a posteriori empirical laws that have been extensively confirmed by experience may, at a later stage of research, be “held fast”, so to speak, irrespective of any further empirical verification, and begin to function as principles that guide the interpretation of certain classes of phenomena. The more these laws are confirmed by experience, and the more effective they are in interpreting subsequent experience, the closer they will come to a priori status. They will eventually be used to define the very empirical concepts they encompass, thus becoming formally analytic. I will show how, in Pap’s perspective, these statements can function as a leading principles for subsequent research and explain their constructive role also. Then, I will explain their relationship with experience and with the other kinds of a priori identified by Pap: the “material” and the “formal” a priori. Finally, I will compare Pap's thesis with other, better-known 20th-century theories of the relativised and dynamic a priori.