Philipp Frank was a central figure in the Vienna Circle, but his ideas vary significantly from those of his peers. Despite the growing body of literature on Frank, his account of simplicity has not yet received the attention it deserves even though it succinctly captures many of the most distinctive elements of Frank's philosophy of science. This is because Frank's account of simplicity is not restricted to the epistemology of scientific theories; his treatment of simplicity provides us with a way of accounting for the influence of social and political agendas on the rejection of scientific theories. In this paper I trace the development of Frank's account of simplicity from 1947 to 1954 and explain how social and political considerations came to inform his mature account in 1954. Furthermore, I demonstrate the continued relevance of Frank's thought by showing that it can be helpfully applied to a contemporary issue associated with the rejection of scientific theories, identity protective cognition.