 Australian-born philosopher Samuel Alexander (1859–1938) was a prominent figure in early twentieth-century British philosophy. He is best known for advancing “British Emergentism”, a movement that held mind “emerges” from matter. Alexander rejected idealism, and accordingly can be labelled a “new realist” alongside the likes of Bertrand Russell; however, unlike other new realists, Alexander maintained close ties with British idealism throughout his career, and his ontology arguably bears similarities to the Absolute Idealism of F. H. Bradley. Alexander’s mature metaphysical system is set out in his greatest work Space, Time, and Deity (1920). Alexander conceives the world as a hierarchy of levels: space and time sit at the lowest level, and through a process of emergence give rise to the levels of matter, life, mind, and deity. These levels are pervaded by “categorial” features of reality, such as substance, universals, and causality. Although Alexander is primarily known as a metaphysician, he wrote extensively on many other philosophical topics, including the history of philosophy, ethics, aesthetics, and the philosophy of religion. Alexander spent most of his professional career at the University of Manchester, where he supported various moves in education and feminism. On his death, Alexander left his philosophical papers and correspondence to the John Rylands Library at Manchester, and this collection constitutes an important philosophic archive of the period.