Volume 43, 2008
Philosophy of Natural Sciences
Diachronic Local Realism about Successful Theories
A major realist response to Laudan-type historical arguments against scientific realism by seeking to identify parts of a successful scientific theory one can claim to have been "essentially" implicated in the theory’s distinctive success, which they regard as primary candidates for realist truth ascription. But, how is one to determine which parts of any theory are "central" or "peripheral", "essential" or "idle" in the required sense? Attempts at spelling out relevant synchronic links between successful predictions and correct partial theorizing increasingly look like a misguided effort. This paper proposes a weaker, but arguably still powerful version of the relation between success and growth of cumulative truth. Focusing on a pivotal case study in recent debates between realists and anti-realists (theories of light in the 19th century), a promising link between success and partial theoretical representation is located in the expansion and stabilization of approximately correct partial modeling of intended domains. The realist link is then formulated accordingly. In the resulting approach (a) predictive success is preserved as a marker of cumulative theoretical gain, but (b) specific gain identification is a diachronic rather than synchronic matter (i.e. specification of particular loci of theoretical gain associated with a given line of predictive success is not assumed to be generally possible at the time of the success in question). The truth ascriptions that get licensed are partial-of a piece-meal and retrospective sort, focused on methodologically specifiable theoretical subplots from past science.