SN 12.16
PTS: S ii 18
CDB i 545
Dhammakathiko Sutta: The Teacher of the Dhamma
translated from the Pali by
Maurice O'Connell Walshe
The Pali title of this sutta is based on the PTS (Feer) edition.

[A monk said:] "'Dhamma-teacher, Dhamma-teacher' they say, Lord."

"If, monk, anyone teaches a doctrine of disenchantment[1] with decay-and-death, of dispassion[2] [leading to] its cessation, that suffices for him to be called a monk who teaches Dhamma.[3]

"If anyone has trained himself in this disenchantment with decay-and-death, in dispassion[4] [leading to] its cessation, that suffices for him to be called a monk who is trained in what is in conformity with Dhamma.[5]

"If anyone, through disenchantment with decay-and-death, through dispassion [leading to] its cessation, is liberated from grasping, that suffices for him to be called one who has attained Nibbaana in this life."[6]

[The same three distinctions are made in respect of birth... ignorance]


Nibbidaa: sometimes rendered "revulsion," but this suffers from the defect of suggesting too strong an emotional reaction. "Disenchantment" covers it better.
Viraaga is quite literally "dis-passion." The syntax of this sentence is rather curious, but the meaning is clear enough.
This gives a clear indication of the minimum standard required for anyone (today, in the West, often a lay person) setting up as a teacher of Buddhism. It denotes a "worldling" (puthujjana, i.e., one who has not "entered the stream") who has the basic intellectual knowledge mentioned here.
This one is a sekha "trainee," i.e., one who has at least "entered the stream" (and thus knows in part from experience), but is not an Arahant.
His training is proceeding along the right path.
He is an asekha ("non-trainee," i.e., one who has finished his training), an Arahant.