On automorphisms of arbitrary mathematical systems
José Sebastião E Silva, A. J. Franco de Oliveira · History and Philosophy of Logic · 1985
Translator's summary The translated paper is an extract, published in 1945, of an unpublished thesis, of both historical and technical import, dealing with notions of definability and their relation to invariance under automorphisms. The author develops a metamathematical Galois theory, and discusses and anticipates some aspects of higher-order model theory in an informal but conceptually rich manner.