Is it discriminatory to reject female candidates for positions of religious leadership; to use different retirement ages for men and women; to have different ages at which heterosexual and homosexual relations become lawful; to impose racial quotas or targets for job recruitment? Is discrimination ever lawful? Is it always evil? This book clarifies the problems about the definition of discrimination. It is chiefly concerned with discriminaiton on the grounds of race and sex, but it also discusses discrimination on other grounds, including those of age, disability and sexual orientation. It explains what philosophy and the social sciences contribute to the analysis of discriminaiton and the effectiveness of the law in combating it. Legal provisions in Britain, the European Community and the United States are outlined but, since national laws are constantly changing, the book concentrates upon internationally accepted principles and the underlying problems that any proposed reforms will have to address.