What really separates casuistry from principlism in biomedical ethics

Since the publication of the first edition of Tom Beauchamp and James Childress's Principles of Biomedical Ethics there has been much debate about what a proper method in medical ethics should look like. The main rival for Beauchamp and Childress's account, principlism, has consistently been casuistry, an account that recommends argument by analogy from paradigm cases. Admirably, Beauchamp and Childress have modified their own view in successive editions of Principles of Biomedical Ethics in order to address the concerns proponents of casuistry and others have had about principlism. Given these adjustments to their view, some have claimed that principlism and casuistry no longer count as distinct methods. Even so, many still consider these two conceptions of bioethical methodologies as rivals. Both accounts of the relationship between casuistry and principlism are wrong. These two conceptions of methodology in biomedical ethics are significantly different, but the differences are not the ones pointed out by those who still claim that they are distinct positions. In this article, I explain where the real similarities and differences lie between these two views.