This review article considers James Griffin's book On Human Rights, which is an immensely important contribution to moral and political thought. The review article starts by explaining why Griffin thinks that the term ‘human right’ suffers from an unacceptable indeterminateness of sense, and then summarizes Griffin's objections to various prominent accounts of human rights. An outline of Griffin's own account of human rights follows. His theory grounds human rights in ‘personhood’ and practicalities. The final section of the article explores Griffin's objections to rule-consequentialism's approach to human rights.