www.blackwell-synergy.com> How to talk about unobservables

An immersed philosopher of science who left this world too early. In this journal, Dicken & Lipton [2006] argued, following Musgrave [1985], that a constructive empiricist cannot coherently draw the distinction between observable objects (events, processes, …) and unobservable ones. We argue to the contrary: the distinction can be drawn coherently, but add a qualification to deal with an associated problem concerning the language of science. 1. Challenges to the Notion of Empirical Adequacy The flaw in those and similar criticisms is that they proceed from the syntactic view of a scientific theory as a set of sentences in a well delineated language. In consequence they take literally the ‘rough and ready ’ characterisation of empirical adequacy of a theory as ‘truth of all that the theory says about observable things’. Constructive empiricism is and has always been wedded to the semantic rather than the syntactic view, precisely because the latter affords no non-trivial concept of empirical adequacy (van Fraassen 1980: 12, 54-55). Musgrave’s argument relied on the account of empirical adequacy tied t