 The general idea of using interpretation to prove consistency was not novel in FG; similar strategies had been recently applied in various mathematical schools to show consistency and independence in arithmetic and in class theory, as well as  geometry.[2]  The technique also has antecedents in the earlier use of geometric models to prove the consistency of non-Euclidean geometries.  [3]  Hilbert’s work in FG brings however a significant advance in terms of the clarity and systematic application of the technique, and an influential account of the nature of the metatheoretic reasoning involved in demonstrating consistency and independence via reinterpretation. Once Hilbert’s technique is applied to the sentences of a fully formalized language, a development that took place in stages over the three decades following FG, we obtain essentially the modern understanding of models, whose use today in demonstrations of consistency and independence differs only in detail from that of Hilbert’s  technique.[4]