Abstract: This chapter examines the Movement's theory of knowledge: the origin of the concept of ethos in Keble's interpretation of Joseph Butler's Analogy, and its subsequent development by Froude Newman and Williams. The Tractarians never described clearly and systematically what they understood for ethos in any of their published works. The chapter tries to map the contributions of different authors to the common theory (or at least to its written expression) in a broadly chronological sequence; two elements central to the concept (‘reserve’ and ‘realizing’) are dealt with in separate sections. The chapter also explores the ‘iconic’ nature that Froude's incarnation of the Catholic ethos had for Newman and the other Tractarians.

Keywords: Butler's Analogy, Keble, Froude, Remains, Newman, Williams, Antiquity, reserve, realizing, principle of personation,