In this profound and profoundly controversial work, a landmark of 20th-century thought originally published in 1971, B F Skinner makes his definitive statement about humankind and society. The book urges us to re-examine the ideals we have taken for granted and to consider the possibility of a radically behaviourist approach to human problems -- one that has appeared to some incompatible with those ideals, but which envisions the building of a world in which humankind can attain its greatest possible achievements.