Johannes Buridan's commentary on Aristotle's Ethics was particularly influential as of the end of the 15th century. Among the passages commented, there is one in which Aristotle develops the distinction between things that are just by nature and those that are legally just and by convention. Buridan's commentary is written in the form of questiones, in which he addresses the Aristotelian text rather freely. From the text it is clear that, according to Buridan, natural law is a rational law. As for influences on the author, it is worth mentioning Albert the Great, Thomas Aquinas and, mainly, Cicero.