We should study the factors which condition dosa-mula-citta. The scriptures and the commentaries show us many aspects of dosa and if we study these aspects we will have more understanding of the disadvantages and the danger of dosa. Right understanding sees the danger of akusala and conditions kusala. It is more beneficial to have right understanding of dosa than just trying to suppress it without any understanding of it.

     There always seem to be numerous causes for dosa and they invariably seem to be outside ourselves: other people's actions or unhappy events which occur. However, the rear cause is within ourselves. Dosa has been accumulated and it can always find an
object. We are attached to pleasant objects and when we do not experience pleasant objects there is bound to be dosa. When dosa arises it shows that the attachment which conditions it must be very strong.

     The Atthasalini (II, Book I, Pan IX, Chapter III, 257) defines dosa as follows:

...It has flying into anger or churlishness as characteristic, like a smitten snake: spreading of itself or writhing as when poison takes effect as function; or, burning that on which it depend (1 Namely, its physical base, which is the heart-base. The rupa which is the physical base of all cittas other than the sense-cognitions of seeing, hearing, etc., is called the heart-base. See Abhidhamma in Daily Life, Chapter 17 ) as function. like jungle-fire; offending or injuring as manifestation. like a foe who has got his chance; having the grounds of vexation as proximate cause, like urine mixed with poison.

     We read that the characteristic of dosa is flying into anger like a smitten snake. When a snake has been hit he h likely to become fierce and attack. Dosa is aggressive, just like a snake which has been hit. The function of dosa is spreading of itself or writhing as
when poison takes effect. When poison has been taken it affects the whole body and it causes suffering. Dosa has likewise an ill effect, it is harmful. The function of dosa is also compared to a jungle-fire which burns that on which it depends. Dosa is destructive
like a jungle-fire which consumes the forest. The proximate cause of dosa are "grounds for annoyance, like urine mixed with poison". Urine mixed with poison is not liked by anybody, although urine was taken as a medicine in India. It is useful to study the proximate cause of dosa, the "grounds for annoyance". Dosa often arises on account of what others are doing or saying to us or to someone else. Even a good deed done to someone else can be a reason for annoyance if we dislike that person. We read in the Book of Analysis (chapter 17, 960) about nine reasons for dosa:

     Therein what are "nine bases of vexation "? "He has done me harm". Thus vexation arises; "He is doing me harm", thus vexation arises: "He will do me harm", thus vexation arises: "He has done harm, … he is doing harm. ... he will do harm to are dear and pleasant to me", thus vexation arises; "He has done good. ... he is doing good. ... he will do good to one not dear and not pleasant to me", thus vexation arises. These are nine bases of vexation.

     Monks, five are lost in hell who lie festering, incurable. What five? (By him) has his mother been deprived life: his father; an arahat: (by him), with evil thought, has the Tathagata’s blood been drawn; (by him) has the Order been embroiled.
      Verily. monks. them are the five lost in hell who lie festering, incurable.
We should remember that all degrees of dosa are dangerous, even the lesser degrees. If we do not develop right understanding we accumulate more and more dosa without realizing it. Therefore, it is helpful to study the different aspects of dosa. 

     We may not have dosa of the intensity to motivate the committing of akusala kamma patha, but even dosa which is of a lesser degree can condition unpleasant behaviour and speech. We can easily, before we realize it, utter harsh speech to someone else. When there is dosa, even if it is a slight annoyance, there is no loving kindness, no consideration for other people's feelings. When, for example, unexpected visitors arrive at a time we do not want to be disturbed, we may be annoyed. At such a moment there is mental rigidity, we are unable to adapt ourselves to a new situation with kindness and hospitality. The Book of Analysis (Chapter 17, 833) gives us a short but very effective reminder in a section in which pairs of realities are summed up (Twofold Summary):

...Absence of softness and inhospitality.

     Dosa can also appear as fear. When there is fear one dislikes the object which is experienced. Fear is harmful for mind and body. One may have fear of people, of situations, of sickness, old age and death. So long as dosa has not been eradicated it will always find an object.

     People have different accumulations: some people may have aversion at certain occasions while others do not. Dosa does not only arise because of what other people do or don't do, it can arise on account of any object experienced through one of the six doors. One may even be cross with the rain, the sun or the wind. We read in the Atthasalini (II, Book II, Part II, Summary, Chapter II, 367):

... "Or when vexation (springs up) groundless" means anger without reason: for example, someone gets angry saying "it rains too much" " it does not rain", "the sun shines too much". "it does not shine "; gets angry when the wind blow, when it does not blow, gets angry at being unable to sweep away the Bodhi leaves, at being unable to put on his robe: he gets angry with the wind, in slipping he gets angry with a tree-stump...

... of what sort, monks, is the one whom mind is like an open sore? Herein a certain person is irritable and turbulent. When anything, no matter how trifling, is said to him, he becomes enraged, he gets angry and quarrelsome: he resents it and displays anger, hatred and sulkiness. Just as, for instance, when a festering sore, if struck by a stick or sherd, discharges matter all the more, even so, monks, a certain person… displays anger, hatred and sulkiness. This one is called "He whom mind is like an open sore"...

     So long as we cling to the pleasant "worldly conditions" (loka-dhammas) of gain, fame, praise and well-being, we are bound to have aversion when they change. They change all tie time but we forget that they are impermanent. When we lose possessions, when we do not receive honour, when we are blamed or when we suffer pain, we have aversion and sadness. Right understanding of realities, of kamma and vipaka, can help us to be more even-minded about pleasant and unpleasant things which happen to us. When we experience unpleasant objects through the senses, it is caused by akusala kamma, by unwholesome deeds which have been committed already, and nobody can avoid akusala vipaka when it is the right time for its arising. When we understand that aversion about akusala vipaka is not helpful, there can be "wise attention" instead of "unwise attention" to the objects which are experienced. There may be intellectual understanding of realities but this understanding cannot eradicate dosa and the other defilements. Only right understanding developed in vipassana can eradicate them.

     Dosa can be temporarily eliminated by the development of calm. When one sees the disadvantages of clinging to sensuous objects and one has accumulations for the development of calm to the degree of jhana, one can be temporarily remote from sense-impressions. Rupavacara kusala cittas (of "fine material jhana") can produce result in the form of rebirth in rupa-brahma planes and arupavacara kusala cittas (of immaterial jhana) can produce results in the form of rebirth in arupa-brahma planes. Although lobha and moha can arise in these planes (1 Except in the rupa-brahma plane which is the asanna-satta plane, the plane of "inconscious beings", where there is only rupa.) , there are no conditions for dosa. However, dosa arises again when there is rebirth in one of the sensuous planes. As we have seen, clinging to sense objects conditions dosa. Only when the stage of the anagami has been attained win dosa be eradicated. The anagami does not cling to sense objects and thus he has no conditions for dosa. 

     Only if we develop right understanding of realities can dosa eventually be eradicated. Right understanding sees dosa as it really is: as sankhara dhamma, conditioned dhamma, non-self. Through mindfulness of dosa its characteristic can be known. We believe that it is easy to recognize dosa, but we usually think of the concept "dosa" or "aversion", and then its characteristic will not be known. We win still take it for "my dosa", instead of realizing that it is only a kind of nama which arises because of conditions.

     It may happen that we have so much aversion about out aversion and about the unpleasant feeling which accompanies it, that we believe that we cannot be mindful of the reality of the present moment. In theory we know that there can be mindfulness of any reality which appears now, but what about the practice? When we see the benefit of right understanding of whatever reality appear, there are conditions for the arising of mindfulness, even when it seems that we are not "in the mood" for it.

     It seems that we do not have hatred or anger, but this does not mean that dosa has been eradicated. So long as there is still the latent tendency of dosa, it can arise any time. We read in the Middle Length Sayings (I, no. 21, The Parable of the Saw) about Videhika who was calm so long as there was no opportunity for dosa. It seemed that she had no dosa at all. She had an excellent reputation, she appeared to be gentle, meek and cairn. Her servant Kali wanted to test her and she came to work later every day. Because of this Videhika lost her temper: she hit Kali on her head with the pin used for securing the door bolt. Because of that she acquired an evil reputation. We read that the Buddha said to the monks:

     Even so, monks, some monk here is very gentle, very meek very tranquil so long as disagreeable ways of speech do not assail him. But when disagreeable ways of speech assail the monk it is then that he is to be called gentle, is to be called meek is to be called tranquil...

     Those who have eradicated dosa, the anagami and the arahat, never have anger nor the slightest displeasure, even in circumstances which are very difficult to bear, even when they have to endure sickness or pain.

     We tend to have aversion when we have pain or when we are sick. When an unpleasant object impinges on the bodysense, body-consciousness accompanied by painful feeling experiences that object. Body-consciousness is vipakacitta, it is in this case the result of akusala kamma. Shortly afterwards in that process of cittas dosa-mula-cittas are likely to arise which experience that object with aversion. It seems almost inevitable that aversion arises after the body-consciousness which experiences an unpleasant object. In order to have right understanding of the different phenomena which occur, it is necessary to develop mindfulness of nama and rupa. There are many different types of nama and rupa when we have pain and when we have aversion about pain, and they can be objects of awareness one at a time. Right understanding of nama and rupa will help us to bear great pains and to be patient in case of sickness. If we begin to develop right understanding of realities at this moment we accumulate conditions for its arising when we are sick or when we are about to die.