Logic of Discovery or Psychology of Invention?

Abstract

This paper can be viewed as an attempt to answer the following two questions: is there in physical science such a thing as rational heuristics, and, if so, how does it operate? Until recently, it was very much part of the orthodoxy in philosophy of science that there is no room for what might be called rational heuristics. Popper, Reichenbach and other members of the Vienna Circle all agreed that there is a sharp distinction between the 'context of discovery' and the 'context of justification'. Only the latter lies within the domain of methodology, whose proper task is to evaluate theories supposed to be laid on the table, i.e. supposed to have already been constructed. As for the context of discovery, it belongs to the psychology of invention. Neither calling for, nor even being susceptible of, any rational reconstruction, the process of discovery allegedly rests on what Einstein called 'empathy with nature'. Most philosophers have said little about how theories arrive 'on the table' in the first place. An exception was Popper in a book entitled Die beiden Grundprobleme der Erkenntnistheorie, which was written in 1930-1 but has only recently been published ([ 1979]). Popper's account of the emergence of new theories is linked to an overall Darwinian world-view: if new theories turn out to explain certain facts, this is not the result of rational and concerted efforts on the part of the scientists; it is an effect of the superabundance of available theories. New hypotheses emerge like spon-