 Stebbing played a major role in the development of analytic philosophy in the 1930s, writing what was in effect the first textbook of analytic philosophy, A Modern Introduction to Logic (1930). Although she was a leading member of the Cambridge School of Analysis, with Moore the strongest influence upon her, she also sought to engage with logical positivism and thereby helped to bring the two together into the wider movement that we now know as analytic philosophy. In her later writings she sought to show the relevance of her logical and analytic work to everyday thinking and to social and political debate. Philosophy and the Physicists (1937) and Thinking to Some Purpose (1939), her two most important books addressed to a more general audience, can also be regarded as among the first books of critical thinking, anticipating developments in sociolinguistics, pragmatics and critical discourse analysis. Both her governing idea of “purposive thinking” and the emphasis she placed on clarity of thought and expression were manifested in all her writing, which was also characterized—as indeed, were her teaching and organizational activities—by an exceptional degree of intellectual honesty and moral integrity.