This was said by the Blessed One, said by the Arahant, as I have heard:

"Bhikkhus, these two bright qualities protect the world. What two? Sense of right and wrong and fear of wrongdoing. If, bhikkhus, these two bright qualities did not protect the world, there would be no recognition of 'mother', 'maternal aunt', 'maternal uncle's wife', 'teacher's wife', or 'the wives of the respected'. The world would fall into confusion, like goats, chickens, pigs, dogs, and jackals. But because, bhikkhus, these two bright qualities protect the world, there is recognition of 'mother', 'maternal aunt', 'maternal uncle's wife', 'teacher's wife', or 'the wives of the respected'."

The Blessed One spoke on this matter. In this regard, it is said:

"Those in whom sense of shame and moral dread, are not present at all times; Have deviated from the root of brightness, and are heading for birth and death.

Those in whom sense of shame and moral dread, are attended to at all times; They grow in the spiritual life, peaceful, they end re-birth."

This matter too was spoken by the Blessed One, as I have heard.