The qualifier “simple” is needed to exclude the following case: Assume that all the models of the theory and the dictionary are finite and all objects have names in the primary system.  Then in each model \(M_i\), each term \(T_j\) of the secondary system is co-extensional with a formula \(\phi_{i,j}\) in the primary system. If furthermore each model is named by a sentential constant \(C_i\) of the primary system, one can define each term \(T_jx_1\ldots x_n\) as the conjunction of the material implications \(C_i \to \phi_{i,j}(x_1,\ldots ,x_n)\) for all models \(M_i\) (220–21).  However, Ramsey (1929a, [FM] 230) argues, apart from being cumbersome, definitions for secondary terms actually hinder scientific development because they require conceptual decisions based on fiat rather than further empirical discoveries (cf. Braithwaite 1953, 52–76). This criticism was later rediscovered by Carnap (1936, 449).