This Very Short Introduction offers a brief survey of the life and key ideas of this most influential Victorian British writer. Moving chronologically, Gregory Claeys outlines the philosophical background out of which Mill developed, chiefly through the ideas of Jeremy Bentham and James Mill. He demonstrates how Mill's personal life, especially his 'mental crisis' of 1827, and his relationship with Harriet Taylor, were integral to his intellectual development. Throughout Claeys considers Mill's key works set within the context of his lesser writings and correspondence, and discusses the more controversial aspects of his thought concerning religion, secularism, and birth control.