 Bolzano was a semantic atomist: in his view, all ideas are ultimately composed of simple parts, which are themselves ideas (TS, §61). In the case of simple ideas with objects, there is no content strictly speaking since there are no parts, and hence no structure either. Thus such ideas are individuated by their extensions alone (TS, §93, no. 3). The relation of a simple idea to its objects is primitive, hence undefinable. It is instructive to compare this position with the contemporary practice of interpreting a formal language by assigning extensions (objects or sets of objects) to the non-logical constants (or parameters).