Mary Warnock and Margaret Thatcher, though they probably never met there, were contemporary undergraduates in wartime Oxford. Their careers diverged after they left university, with Margaret Thatcher going on to a stellar career in politics, culminating in her election as the first female Prime Minister. Mary Warnock spent her first seventeen years as an Oxford philosophy don, teaching undergraduates and postgraduates, writing a significant text on ethics and a number of books on existentialism while bringing up five children. She was then appointed headmistress of Oxford High School for Girls before chairing two government committees, one on special education and one on assisted reproduction which produced reports which have remained significant to this day. The careers of both of these women spanned a half-century in which, though gender equality was far from achieved, there were massive improvements in the opportunities available especially to middle-class white women. These are described in some detail. Mary Warnock was not radical in her views, describing herself as a ‘conservative feminist’, but she was immensely encouraging to ambitious women and was herself a role model for many. In contrast, Margaret Thatcher, while articulating a feminist position, did nothing to promote the careers of women even when it was in her power to do so. In her memoir, written at the end of the century, Mary devoted a chapter to Margaret Thatcher, whose values she loathed. Margaret Thatcher had a massive impact on the national and international scene, and it is appropriate that there should be numerous biographies of her. The life and work of Mary Warnock, whose contributions made a significant contribution towards creating a more decent society, is so far unrecorded. This book aims to fill the gap.