Al-Shafi'i (d. 820) is clearly one of the most important figures in the early history of Islamic jurisprudence. His Risala or "Treatise" on the "principles of jurisprudence" (usul al-fiqh) is also of interest as an example of an approach to ethics that focuses on divine commands. Following a brief introduction, I offer the reader a few comments about al-Shafi'i's context. I summarize the content of the Risala and then analyze it as an example of divine command reasoning in ethics. Finally, (...) I present some observations on the place of al-Shafi'i's theory in the history of Islamic ethics, particularly with respect to his comments on ikhtilaf, "disagreement.". (shrink)