 A more comprehensive account of the historical roots of structuralism in philosophy of science can be found in Bolinger (2016), although this book is not yet translated into English. The seminal book was Sneed (1971) which presented a meta-theory of physics in the model-theoretical tradition connected with P. Suppes, B. C. van Fraassen, and F. Suppe. This approach was adopted and popularized by the German philosopher W. Stegmüller (1923–1991), see e.g., Stegmüller (1979b) and further developed mainly by his disciples. In its early days the approach was called the “non-statement view” of theories, emphasizing the rôle of set-theoretical tools as opposed to linguistic analyses. Later this aspect was considered to be more of practical importance than a matter of principle, see Balzer et al. (1987, 306 ff). Recently, H. Andreas (2014) and G. Schurz (2014) have proposed two slightly different frameworks that reconcile semantical and syntactical formulations of Sneed’s program. Nevertheless, the almost exclusive use of set-theoretic tools remains one of the characteristic stylistic features of this program and one that distinguishes it conspicuously from the other programs.