Once, when the Buddha was at Campā, on the banks of Lake Gaggarā, he was visited by Pessa, the elephant trainer's son, and Kandaraka, the Wanderer. Pessa saluted the Buddha and sat down, while Kandaraka, after his salutation, remained standing. Surveying the assembly of monks gathered round the Buddha and observing their great silence, Kandaraka expressed his admiration of the Buddha's training. The Buddha explained that all Buddhas school their disciples in the four satipatthānas. Pessa stated that it was far more difficult to train men than animals. The Buddha agreed and enumerated the four kinds of people in the world: those who torment themselves, torment others, torment both themselves and others, and, lastly, those who torment neither, dwelling beyond appetites, in bliss and holiness. Pessa stated that he respected only the fourth class, and having given his reasons went away. The Buddha expressed his regret that Pessa could not wait to hear the differences between these four kinds of people; and at the request of the monks the Buddha proceeded to describe them (M.i.339ff).