In Patience the Gawain-Poet makes the point that when ordered to do something it is useless to resist or to show displeasure

The same attitude was instilled in the young princes of the Portuguese court by their tutors, including James Cottrell.  Fernão Lopes is paraphrased by Russell [RUSSELL01] (p.22) “The chronicler (Fernão) goes on to assert that, even when he (João) called upon them (his sons) to do something of which they themselves disapproved, they carried it out without showing a sign of their inner feelings”.