Renouncing pain and pleasure is Sannyasa - Majjhima Nikaya 14

The Buddha Gotama said to Mahanama, a Sakyan in Kapilavatthu,

Ignorance, hatred and desire, when they enter into the mind and are permitted to remain, prevent accurate perception of things. It is wrongly taught that non-reaction to ignorance, hatred and desire results in their passing away, as if their passing away were natural: these are not emotions, and though emotions arise, stay a while, and pass away, ignorance, hatred and desire, if permitted to remain, will remain. These must be renounced: does a householder who has renounced the world to enter Sannyasa remain a householder? No, if a householder does not renounce the world, they remain a householder.

Why do people not renounce ignorance, hatred and desire? These have the allure of sensation, some of which is pleasurable, some of which is painful. A person reacts to the pleasure by seeking more pleasure, and react to the pain by avoiding the pain: both aversion to pain and preference for pleasure result in more sensation, more ignorance, hatred and desire. If, however, this is understood as a cause of suffering, ignorance, hatred and desire may be renounced. Before I awakened, when I was a householder, I came to this very understanding.

What is the means of pleasure and pain from ignorance, hatred and desire? The eye, the ear, the nose, the tongue, the body's skin. Things are seen, heard, smelled, tasted and touched, and discerned as pleasurable, or painful. Yet though each accurately perceives the world, it is the interpretation of the perception as painful or pleasurable is responsible for ignorance, hatred and desire. There are no austerities which can wholly remove what is seen, heard, smelled, tasted and touched; no austerities can prevent the interpretation of the senses - of sensuality - as pleasurable or painful.

When a householder engages upon an occupation, it is the same as when a Sannyasi renounces the world. The householder must make a living - whether it is accounting, calculating, plowing, trading, farming, soldiering, or even as a Kingsman. Whatever the occupation, they face cold, heat, are harassed by mosquitoes and flies, wind and sun, dying from hunger and thirst - numerous annoyances, numerous sensory experiences which are difficult to bear. And if while working hard, striving and making good effort, skillfully doing their job, the householder gains no wealth, no honor, no reward, they will sorrow, grieve and lament, become distraught, saying "My work is in vain, my efforts fruitless!" So too will a Sannyasi grieve at their lack of success if they attempt to conquer their ignorance, hatred and desire by austerities.

When a householder succeeds and gains wealth and honor, they become pre-occupied by how to protect it against their enemies, thieves, fire, flood even their own kin, their own King, their own friends. They develop greed, and attachment. And when, inevitably, they lose what they gained, they become distressed - for they see their success, their wealth and honor, only as the reward for their sacrifices of discomfort. They believe their discomfort was for nothing. "What is mine is no more!" Should not a Sannyasi similarly view the inevitable arising of ignorance, hatred and desire? The householder rebuilds from a fire or flood, recovers from theft, bears taxes and must remain generous - the desolation is not permitted to remain. So too must ignorance, hatred and desire not be permitted to remain.

Without generosity, a householder quarrels and fights with their friends, their family, hide their wealth from the King, even bear arms against the King. They fight first with fists, then sticks, then knives - until they kill their enemy, for the quarreling itself becomes a sensual experience. They draw others into their fight, and then there are armies, destroying the work of numerous householders, killing and hurting numerous householders. Why should a Sannyasi war against themselves, against their nature - depriving themselves of pleasure and pain, depriving themselves of sensuality through austerities? Would it not be better to engage their ignorance, hatred and desire?

It is by such sensuality that people lose their ability to reason, and in their madness they will burgle, plunder, commit robbery, adulter - and torture those they believe to be criminal, first by locking them in a room for years at a time, then by flogging, then by beating, then by mutilation, then by death.  Has punishing criminals ever resulted in lawful behavior or their reform?  It is sadism to cause pain without purpose, and be satisfied by causing pain: would it not be more satisfying to reform a criminal?  People easily become sadistic when they permit ignorance, hatred and desire to remain, justifying their actions by thinking that this is the way that reason is restored, that law and order is restored. But they are only contributing to their own madness, and the madness of others. It is madness to think that pain - or pleasure - will result in the ending of sensuality, the ending of ignorance, hatred and desire.