In "Animals and Why They Matter", Mary Midgley examines the barriers that our traditions have erected between man and animals, and argues that the often ridiculed subject of animal rights is an issue crucially related to such problems within the human community as racism, sexism, and age discrimination. The book brings together two intellectual currents: an increased scientific understanding and public appreciation of animals, and an increasing tendency by philosophers to extend moral questions beyond the barrier of our own species. Mary Midgley has published "Beast and Man", on the topic of human uniqueness, and "Heart and Mind", on moral psychology.