In a later paper, Church turns his attention to a paradox that Russell formulates in Appendix B of Principles of Mathematics (1903). Once again, Church’s aim is first to show how this contradiction arises in STT, and then to appeal to RTT as a means of solving the problem. This time, however, STT is not supplemented directly by any overt semantic principles concerning denotation or predication, but only by a predicate for identity of propositions and axioms supporting Russell’s view as of 1903,