[442] Bhikkhus, there are these three characteristics of a fool (bālalakkhaṇāni), signs of a fool (bālanimittāni), and habitual conduct of a fool (bālāpadānāni). What three? Here, bhikkhus, a fool is one who thinks badly-thought thoughts, one who speaks badly-spoken speech, and one who does badly-done deeds. If, bhikkhus, a fool were not one who thinks badly-thought thoughts, one who speaks badly-spoken speech, and one who does badly-done deeds, by what means would the wise know him thus: "This person is a fool, not a true person"? But because, bhikkhus, a fool is one who thinks badly-thought thoughts, one who speaks badly-spoken speech, and one who does badly-done deeds, therefore the wise know him thus: "This person is a fool, not a true person." These, bhikkhus, are the three characteristics of a fool, signs of a fool, and habitual conduct of a fool.
Bhikkhus, there are these three characteristics of a wise person (paṇḍitalakkhaṇāni), signs of a wise person, and habitual conduct of a wise person. What three? Here, bhikkhus, a wise person is one who thinks well-thought thoughts, one who speaks well-spoken speech, and one who does well-done deeds. If, bhikkhus, a wise person were not one who thinks well-thought thoughts, one who speaks well-spoken speech, and one who does well-done deeds, by what means would the wise know him thus: "This person is wise, a true person"? But because, bhikkhus, a wise person is one who thinks well-thought thoughts, one who speaks well-spoken speech, and one who does well-done deeds, therefore the wise know him thus: "This person is wise, a true person." These, bhikkhus, are the three characteristics of a wise person, signs of a wise person, and habitual conduct of a wise person.
Therefore, bhikkhus, you should train thus: "We shall shun the three qualities possessed of which one is to be known as a fool, and we shall undertake and practise the three qualities possessed of which one is to be known as a wise person." It is thus, bhikkhus, that you should train.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.