  Scientific realism became dominant in philosophy of science after the demise of the forms of antirealism about science associated with the logical positivists, namely semantic instrumentalism, according to which theoretical terms are not to be interpreted as referring to anything, and theoretical reductionism, according to which theoretical terms are disguised ways of referring to observable phenomena. These forms of antirealism rely upon discredited doctrines about scientific language, such as that it can be divided into theoretical and observational parts, and that much of it should not be taken literally. Bas van Fraassen (1980) revitalised the debate about scientific realism by proposing his constructive empiricism as an alternative. His antirealism is sceptical rather than dogmatic, and does not depend on the distinction between theoretical and observational terms. He allows that terms such as ‘sub-atomic particle’ and ‘particle too small to see’ are perfectly meaningful and should be taken literally (note that the former term is theoretical and the latter term is not but both purportedly refer to unobservable entities). On the other hand, he holds that it is perfectly rational to remain agnostic about whether there are any such particles because he argues that to accept the best scientific theories we have only requires believing that they are empirically adequate, in the sense of correctly describing the observable world, rather than believing that they are true simpliciter. (For more on constructive empiricism see Monton 2007.)