E. E. Constance Jones (1848–1922) published widely in philosophical logic and in ethics and moral psychology and was an active member of the British philosophical community from 1890 until her death. Her contributions to philosophical logic were wide-ranging and sophisticated, anticipating celebrated insights of later twentiethcentury philosophy of language and logic. In ethics, her writings on hedonism and practical reason, though influenced by her mentor, Henry Sidgwick, were innovative and merit further examination.