This book examines the controversial and repercussive contention that an objective of the law should be to promote personal morality - to make people ethically better. It surveys a number of domains, including criminal law, tort law, contract law, family law, and medical law (particularly the realm of moral enhancement technologies) asking for each: (a) Does the existing law seek to promote personal morality? (b) If so, what is the account of morality promoted, and what is the substantive content? (c) Does it work? and (d) Is this a legitimate objective?