How do Catholic scholars explain the limited definition of perfection, as given by James in 3:1-2?

We read in James 3:1-2: >Not many of you should become teachers, my brothers and sisters, for you know that we who teach will be judged with greater strictness. For all of us make many mistakes. Anyone who makes no mistakes in speaking is perfect, able to keep the whole body in check with a bridle. We also see Jesus saying in Mtt 15:18-20: > But what comes out of the mouth proceeds from the heart, and this defiles a person. For out of the heart come evil thoughts, murder, adultery, sexual immorality, theft, false witness, slander. These are what defile a person. We see that Jesus is emphasizing on thought process, in judging a person's character, while James emphasizes on spoken words. Of course, the contexts are different, and James has a limited issue to deal with namely, selection of teachers of the church. But one wonders whether James given too much importance to gift of the tongue. My question therefore is: **How do Catholic scholars explain the limited definition of perfection, as given by James in 3:1-2?**