Anthony was the first of the brothers to teach theology to the friars. The letter Francis wrote to him about this is one of my favorites:
Fratri Antonio episcopo meo frater Franciscus salutem. Placet mihi quod sacram theologiam legas fratribus, dummodo inter huius studium orationis et devotionis spiritum non exstinguas, sicut in regula continetur.
Greetings from brother Francis to brother Anthony, my bishop. It pleases me that you teach sacred theology to the brothers, so long as, amidst this study, you do not extinguish the spirit of prayer and devotion, as contained in the rule.
For a couple of nice feast of St. Anthony posts, check our Chiara and Frater.