Morality: Its Nature and Justification is a new edition of philosopher Bernard Gert's distinctive and comprehensive moral theory. This final revision answers all of the criticism his work has attracted over 30 years.

Gert's account of morality as a public system that applies to all rational persons is the only objective account of morality that allows for limited moral disagreement. It explains why abortion and the treatment of animals are such controversial issues, justifies deciding some moral problems by voting, and explains the prevalence of hypocrisy.