 Van Fraassen (1980) reinvented empiricism in the scientific context, evading many of the challenges faced by logical empiricism by adopting a realist semantics. His position, “constructive empiricism”, holds that the aim of science is empirical adequacy, where “a theory is empirically adequate exactly if what it says about the observable things and events in the world, is true” (1980: 12; p. 64 gives a more technical definition in terms of the embedding of observable structures in scientific models). Crucially, unlike logical empiricism, constructive empiricism interprets theories in precisely the same manner as realism. The antirealism of the position is due entirely to its epistemology—it recommends belief in our best theories only insofar as they describe observable phenomena, and is satisfied with an agnostic attitude regarding anything unobservable. The constructive empiricist thus recognizes claims about unobservables as true or false, but feels no need to believe or disbelieve them. In focusing on belief in the domain of the observable, the position is similar to traditional instrumentalism, and is for this reason sometimes described as a form of instrumentalism. (For elaborations of the view, see van Fraassen 1985, 2001 and Rosen 1994.) There are also affinities here with the idea of fictionalism, according to which things in the world are and behave as if our best scientific theories are true (Vaihinger [1911] 1923; Fine 1993).