361. Again, it may be understood by a person’s conversation whether or not he is competent to discuss things. If, on being questioned, a person evades the question, changes the subject, displays anger, malice or sulkiness, then he is incompetent to discuss things. If a person does not do these things, then he is competent to discuss.
Yet again, it may be understood by a person’s conversation whether or not he is competent to discuss. If, on being asked a question a person loads scorn on and beats down the questioner, laughs at him and tries to catch him up when he falters, then he is incompetent to discuss things. If a person does none of these, then he is competent.
Anguttara Nikaya I.197
http://www.buddhavacana.net
Cattāri Brahmavihārā 
Leave a comment