ABSTRACT
Rapidity of progress, or at least change, in the analysis of scientific theory structure is indicated by the fact that only a few years ago the natural question to ask would have been ‘Is there an independent theoretical language?’… Now however, several radical and fashionable views place the onus on believers in an observational language to show that such a concept has any sense in the absence of a theory (Hesse, 1974 (1970) p. 9).
