Glass Houses
Sages do not hesitate to criticize the harmful behaviour of others. They see others as their own self, and regard all wisdom and ignorance as their own. They do not wait to be asked their opinion. They never hesitate to speak when a word needs to be said. They will speak harshly towards our most deeply cherished beliefs - if those beliefs be in error.
False teachers, however, do not criticize others; they live in glass houses and fear for their own safety. They do not wish to make enemies. They know their own ideas and values have no basis in reason, so are ashamed to offer them up for public scrutiny. The last thing they want is to end up on the receiving end of other people's advice.
Someone who cannot swim does not rock the boat.