This chapter traces the development of Stebbing’s thinking about philosophical analysis, drawing on her published works, but also on her correspondence with G. E. Moore. These letters provide evidence of her response to Russell’s theory of descriptions and his account of incomplete symbols, which informed her writing of A Modern Introduction to Logic (1930), her rewriting of the book for its second edition (1933) and the subsequent development of her thinking about analysis. Her dissatisfaction with Russell’s apparent confusion between the analysis of propositions and the discovery of basic facts led her to propound ideas about ‘directional’ analysis which were to become foundational to the Cambridge School of Analysis. The reconsideration of some of Stebbing’s most influential published works in the light of her unpublished correspondence with Moore has both particular and more general significance. Firstly, while confirming the importance to Stebbing of her professional relationship with Moore, the letters serve to debunk any misconception that she was straightforwardly his ‘follower’. Secondly, recent scholarship has emphasised the importance of Cambridge analysis to the development of analytic philosophy in the mid-twentieth century. An understanding of the genesis of this period in Stebbing’s work, informed by archival as well as by published sources, is therefore of importance to the wider history of analytic philosophy.