Dosa can arise on account of the objects experienced through the five sense-
doors and the mind-door. It can arise when we see ugly sights, hear harsh
sounds, smell unpleasant odours, taste unappetizing food, experience
unpleasant tangible objects through the bodysense and think of disagreeable
things. Whenever there is a feeling of uneasiness, no matter how slight, it is
evident that there is dosa. Dosa may often arise when there is the experience
of unpleasant objects through the senses, for example, when the temperature
is too hot or too cold. Whenever there is a slightly unpleasant bodily sensation
dosa may arise, be it only of a lesser degree.
Dosa arises when there are conditions for it. It arises so long as there is still
attachment to the objects which can be experienced through the five
senses. Everybody would like to experience only pleasant things and when
one does not have them any more, dosa may arise.
Another condition for dosa is ignorance of Dhamma. If we are ignorant of kamma and vipāka, cause and result, dosa may arise very easily on account of an unpleasant experience through one of the senses and thus dosa is accumulated time and again. An unpleasant experience through one of the senses is akusala vipāka caused by an unwholesome deed we performed. When we, for example, hear unpleasant words from someone else, we may be angry with that person. Those who have studied the Dhamma know that hearing something unpleasant is akusala vipāka which is not caused by someone else but by an unwholesome deed performed by oneself. A moment of vipāka falls away immediately, it does not stay. Are we not inclined to keep on thinking about an unpleasant experience? If there is more awareness of the present moment one will be less inclined to think with aversion about one's akusala vipāka.