Adosa can be translated as non-aversion or non-hate, but there are many forms and degrees of it, loving kindness, metta, is a form of adosa which is directed towards living beings. Adosa can also be non-aversion with regard to an object which is not a being and then it can be described as patience. There can be non-aversion or patience with regard to heat, cold, bodily pain or other unpleasant objects.

    The Atthasalini (I, Book I, Part IV, Chapter 1, 127) defines non-aversion, adosa, as follows: 

... Absence of hate has the characteristic of freedom from churlishness or resentment, like an agreeable friend; the function of destroying vexation, or dispelling distress, like sandalwood: the manifestation of being pleasing, like the full moon...

     The function of non-aversion is the removing of annoyance or vexation and non-aversion is compared to sandalwood which has a very agreeable odour and is said to cure fever. When there is aversion we are vexed and annoyed; we burn with the fever of hate and we may become uncontrolled, we may not know what we are doing. Aversion is like a fire, it is hard to extinguish. However, when non-aversion arises we are cured of the fever of aversion, all annoyance has gone.

     Both aversion and non-aversion influence our bodily disposition. We read in the Atthasalini (I, Book I, Part IV, Chapter I, 129) :

... Absence of hate is the cause of youthfulness, for the man of no hate, not being burnt by the fire of hate, which brings wrinkles and grey hairs, remains young for a long time...

... Absence of hate is the cause of the production of friends, for through love friends are obtained, not lost...

     When we observe sila there is non-aversion accompanying the kusala citta. When we abstain from akusala kamma which harms both ourselves and others we show an act of kindness. The Atthasalini (in the same section) states:

     Good-will is that which does not ruin one's own or another's bodily or mental happiness, worldly or future advantage and good report. 

     We read in the Kindred Sayings (I, Sagatha-vagga, Chapter XI, Sakka Suttas, I, 4) that Sakka, ruler of the gods, was reviled by Vepacitti, an Asura (a demon). Sakka explained to Matali, the charioteer, that it was not because of weakness that he showed forbearance. He praised patience and forbearance and he said:

... Worse of the two is he who, when reviled,
Reviles again. Who does not, when reviled,
Revile again, a twofold victory wins.
Both of the other and himself seeks
The good: for the other's angry mood
Does understand and grows calm and still.
He who of both is a physician, since
Himself he  heals and the other too,
Folk deem him fool, they knowing not the Dhamma...

     Kindness, metal, is a form of adosa which is directed towards living beings. Patience, as we have seen, is another aspect of adosa. There can be patience with regard to beings and also with regard to objects which are not beings, thus with regard to all objects which can be experienced through the six doors. When there is aversion towards unpleasant objects there is no patience. When we have to endure hardship it may be difficult not to have aversion, but when non-aversion arises we can endure what is unpleasant. The Buddha exhorted the monks to endure unpleasant objects. We read in the Middle Length Sayings (I, no. 2, Discourse on All the Cankers) that the Buddha spoke about different ways of getting rid of the cankers and he explained that one of these ways is endurance. It is to be understood that the cankers cannot be eradicated unless right understanding is developed. We read:

     And what, monks, are the cankers to be got rid of by endurance? In this teaching, monks, a monk wisely reflective, is one who bears cold, heat, hunger, thirst, the touch of gadfly, mosquito, wind and sun, creeping things, ways of speech that are irksome. unwelcome: he is of a character to bear bodily fillings which, arising, are painful, acute, sharp, shooting, disagreeable, miserable, deadly. Whereas, monks, if he lacked endurance, the cankers which are destructive and consuming might arise. But because he endures, therefore these cankers which are destructive and consuming are not. These, monks. are called the cankers to be got rid of by endurance.

     One of the hardest things to endure is the separation from those who are dear to us. We read in the Gradual Sayings (IV, Book of the Sevens, chapter V, $ 10) about Nanda's mother, an anagami, who had through the development of right understanding eradicated aversion. After she had offered dana to the monks with Sariputta and Moggallana at their head she testified to Sariputta about marvellous things which had happened to her We read:

"... Rajahs, for some reason, took by force and slew my only son, Nanda, who was dear and precious to me; yet when the boy was seized or being seized. bound or being bound, slain or being slain. I knew no disquietness of heart."
   "It is marvellous and wonderful, O mother of Nanda, that you should have so purged the surges of the heart."
   "Nor is that all, reverend sir... When my husband died, he rose among the yakkas (1 Non human beings) ; and he revealed himself me in his old form; but l knew no disquietness of heart on that account." 

     The anagami or "non-returner", who has attained the third state of enlightenment, has no more attachment to sensuous objects and thus, when there is an unpleasant object instead of a pleasant object, he has no conditions for aversion. Nanda's mother who was an anagami, had no sadness, fear or anxiety, no matter what happened to her. If we understand that attachment to people can lead to utter distress when we lose them, we may see the danger of attachment, and then we can be reminded to develop right understanding which leads to the eradication of all defilements.

     In the development of right understanding patience has to be applied. When there are many moments of akusala citta we should have patience to be mindful even of akusala citta. When there is aversion we may be annoyed about it, or we may take it for my aversion". When there is mindfulness of aversion it can be known as only a type of nama which has arisen because of its appropriate conditions. At the moment of mindfulness there is non-aversion, adosa, instead of aversion, dosa.

     Loving kindness, metta, is, as we have seen, a form of adosa which is in particular directed towards living beings. The Visuddhimagga (Chapter lX, 93) gives, apart from the definition of non-aversion, a definition of loving kindness or metta :

As to characteristic, etc., loving kindness is characterized here as promoting the aspect of welfare. Its function is to prefer welfare. It is manifested as the removal of annoyance. lts proximate cause is seeing lovableness in beings. It succeeds when it makes ill-will subside, and it fails when it produces (selfish) affection.

     The "near enemy" of loving kindness is selfish affection, attachment. Attachment tends to arise very closely after moments of loving kindness but we may not notice this. We should find out whether we want to be kind only to people we particularly Like, or whether we are kind to whomever we meet, because we are truly concerned for his welfare. From our own experience we can learn to see the difference between loving kindness and selfish affection. If we are attached to someone we will miss him when he is no longer with us; attachment conditions aversion. When there is loving kindness we do not think of our own enjoyment in someone's company. When loving kindness arises, there is detachment, alobha, and also equanimity or impartiality (tattramajjhattata).

     When we are giving a gift to someone or when we are helping someone, there may be pleasant feeling. However, instead of pure loving kindness there can be attachment. We should remember that pleasant feeling can arise with kusala citta as well as with citta rooted in attachment. We find pleasant feeling very important and we tend to think that it is kusala all the time, but we can easily be misled by pleasant feeling. 

     When loving kindness arises there is not necessarily pleasant feeling all the time. Kusala citta can be accompanied by pleasant feeling or by indifferent feeling.

     The Visuddhimagga (Chapter IX) gives advice for the application of loving kindness for someone who is inclined to give in to anger. He should review the danger in hate and the advantage of patience. A person harms himself when he is angry. When he is angry with someone he should not pay attention to the bad qualities of that person but only to his good qualities, and if he has none he should be compassionate instead of angry. That person's accumulation of akusala will bring him sorrow. We should remember that we all are "heirs" of our deeds, we will receive the results of our deeds.

     We could also regard the person we are angry with as five khandhas (aggregates) or as elements which are impermanent These arise and then fair away immediately and thus what is then the object we are angry with? The citta of the other person which motivated unpleasant speech or an unpleasant deed has fallen away already and thus it belongs to the past. Another way of overcoming anger is giving a gift. We can learn from experience that, when we give a gift, there are conditions for kusala citta both for the giver and the receiver. Giving and receiving mellows the heart and thus the relationship between people can be improved

     We could also, in order to have less anger and more loving kindness, reflect on the virtues the Bodhisatta accumulated. We read in the Visuddhimagga (IX, 26) about the way of reviewing these:

... is it not the fact that when your Master was a Bodhisatta before discovering full enlightenment, while he was still engaged in fulfilling the Perfections during the four incalculable ages and a hundred thousand aeons. he did not allow hate to corrupt his mind even when his enemies tried to murder him on various occasions? For example, in the Silavant Birth Story (Jatakas I, 26I ) when his friends rose to prevent his Kingdom of three hundred leagues being seized by an enemy king who had been incited by a wicked minister in whose mind his own queen had sown hate for him, he did not allow them to lift a weapon. Again when he was buried. along with a thousand companions, up to the neck in a hole dug in the earth in a charnel ground, he had no thought of hate. And when, after saving his life by a heroic effort helped by jackals scrapping away soil when they had come to devour the corpses, he went with the aid of a spirit to his own bedroom and saw his enemy lying on his own bed, he was not angry but treated him as a friend, undertaking mutual pledge, and he then exclaimed:
     "The brave aspire, the wise will not lose heart 
I see myself as I had wished to be. " (Jatakas I. 267)

     Loving kindness is one of the meditation subjects of samatha. Those who have accumulated conditions for the development of calm to the degree of jhana can attain jhana with this meditation subject (1 With this subject different stages of rupa-jhana can be attained ,but not the highest stage, since the jhanacittas of the highest stage (the fourth in the fourfold system and the fifth in fivefold system) are accompanied by indifferent feeling. Loving kindness can be accompanied by pleasant feeling or by indifferent feeling and thus it is not the object of the highest stage of jhana.) . Loving kindness (metta) is among the four meditation subjects which are called the " divine abidings" (brahma-viharas). The other three "divine abidings" are: compassion (karuna), sympathetic joy (mudita) and equanimity (upekkha). They are called divine abidings because they are excellent and of a "faultless nature": those who cultivate them live like the "Brahma divinities" (Atthasalini, I, Book I, Part V, Chapter XII, 195). The divine abidings are also called "Illimitables" (appamannas) because they arise in an immeasurable field, their field or object is beings without Iimits. Loving kindness, for example, can, when jhana is attained with this subject, be extended to all beings, none excepted.

     Loving kindness is sublime and it can be illimitable, but even the most excellent qualities are impermanent and dukkha. Without the development of right understanding good deeds, excellent virtues or even jhana cannot lead to the end of defilements. The final goal of the Buddha's teachings is the eradication of defilements and this means the end of dukkha.

     Through the development of fight understanding the clinging. to the self can gradually decrease, and as a consequence there will be more conditions for loving kindness and patience. One will be more inclined to help others without selfish motives. There are many degrees of non-aversion, adosa, and in the arahat non aversion has reached perfection. Those who have attained enlightenment, the ariyans, do not have wrong view of people who exist; they have realized that there are only nama and rupa, but they can still think of the concept "being". The arahat can think of "being" but he thinks of beings without any defilements Those who have eradicated defilements ate truly kind to all beings.