Friendship with the upright, with the truthful and with the well informed is beneficial. Friendship with those who flatter, with those who are meek and who compromise with principles, and with those who talk cleverly is harmful.
I do not enlighten those who are not eager to learn, nor arouse those who are not anxious to give an explanation themselves. If I have presented one corner of the square and they cannot come back to me with the other three, I should not go over the points again.
How abundantly do spiritual beings display the powers that belong to them! We look for them, but do not see them; we listen to, but do not hear them; yet they enter into all things, and there is nothing without them.