The article presents a general introduction to the commentaries on the Nicomachean Ethics written by Protestant authors during the 16th century. A unilateral view of the intellectual history of this period, caused by Luther's anti-Aristotelianism, is thus corrected. The article attends to the way in which these authors address the natural law text of EN V, 7, particularly their discussion of the peculiarly Aristotelian thesis about the mutability of natural law.