 Carnap (1958; 1966: ch. 26) attempted to attain a metaphysically neutral position so as to avoid any commitment to or denial of scientific realism. In his account of the theoretical language of science, theoretical entities were conceived of as mathematical entities that are related to observable events in certain determinate ways. An electron, for example, figures as a certain distribution of charge and mass in a four-dimensional manifold of real numbers, where charge and mass are real-valued functions. These functions and the four-dimensional manifold itself are to be related to observable events by means of universal axioms. Notably, Carnap would not have accepted a characterization of his view as antirealist or non-realist since he thought the metaphysical doctrine of realism to be void of content.