Following a detailed and sophisticated review of legal theory and practice Buchanan concludes that legal tests of excuse and mitigation boil down to two questions. The first is `did he have it?' (intent). The second is `did he do it?' (action)...Buchanan argues that such an approach fails the severely mentally ill by not taking account of the extent of the underlying disability...the general detail and sophistication of Buchanan's discourse will justifiably serve to establish this slim volume as a standard reference.