Understanding, panna or amoha, is among the six sobhana cetasikas which do not accompany each sobhana citta. It is one of the three beautiful roots, sobhana hetus. The two sobhana hetus which are non-attachment, alobha, and non-aversion, adosa accompany each sobhana citta, but understanding does not. Whenever we perform deeds of generosity or observe morality understanding may or may not accompany the kusala citta. But when we apply ourselves to mental development, bhavana, which comprises studying the teachings and explaining them to other the development of samatha and the development of vipassana, understanding has to accompany the kusala citta.

     When understanding accompanies the maha-kusala citta (kusala citta of the sense-sphere) which performs deeds of generosity or observes morality, it may be of the level of intellectual understanding: understanding of the benefit of good deeds and the disadvantages of bad deeds, understanding of kamma and vipaka. However, when we perform deeds of generosity or observe morality, there can also be the development of direct understanding of realities. 

     As regards mental development, one cannot apply oneself with success to this way of kusala without understanding. Also those who do not know the Buddha's teachings may reflect wisely on the truth that all things in life are susceptible to change and that they do not last, and they may develop calm. There were wise people also before the Buddha's time who understood the characteristic of true calm which is wholesome. Those who understood the characteristic of calm and did not mistakenly think that clinging to quietness was calm, could develop calm with a meditation subject and in this way attain higher degrees of calm. Those who saw the disadvantages of sense-impressions developed jhana in order to be free of them. Those who saw the disadvantages of rupa-jhana, fine-material jhana, which still has meditation subjects depending on materiality, developed arupa-jhana, immaterial jhana. The person who had become very skilful in jhana could develop "supernormal powers", abhinnas, such as magical powers, remembrance of former lives and the "Divine Eye", knowledge of the passing away and rebirth of beings. The cittas which develop such powers are accompanied by understanding, but even this kind of understanding cannot eradicate defilements.

     The understanding which realizes the true nature of realities can eradicate defilements and its development can only be taught by a Buddha. This kind of understanding does not arise automatically, it has to be developed. When one has listened to the Dhamma and reflected on it, there can first be intellectual understanding of realities. If there is mindfulness of nama and rupa when they appear in daily life direct understanding of realities can gradually be developed. Eventually the true nature of realities can be penetrated and defilements can be eradicated at the attainment of enlightenment (1 Intellectual understanding is in Pali: pariyatti. The development of direct understanding or tile "practice" is in Pali: patipatti. The penetration of the truth is in Pali: pativedha.).

     Seeing realities as they are is the goal of the Buddha's teachings. Understanding should know what is real in the ultimate sense and what is not real. So long as there is wrong view we cannot see things as they are. People, animals and houses are not real in the ultimate sense, they are only objects of thought. Nama and rupa are real in the ultimate sense, they have their own characteristics which can be directly experienced when they appear one at a time, through one of the six doors. We can verify the truth of the Buddha's teachings in being mindful of realities and developing understanding of them. Then we will be able to find out whether realities are permanent or impermanent, whether there is a person or self who can control realities or not.

     Each reality has its own specific characteristic by which it can be distinguished from another reality (distinctive mark or visesa lakkhana. Seeing, hearing, hardness or sound have each their own characteristic. However, there are also three general characteristics common to all conditioned realities (samanna lakkhana) and these are: impermanence, dukkha or unsatisfactoriness, and anatta, non-self. When understanding has been developed it can eventually know realities as impermanent, dukkha and anatta. There cannot, in the beginning, be clear understanding of the true nature of realities. Understanding develops gradually in different stages. 

     Direct understanding of realities is, as we have seen, different from thinking about them. Direct understanding can only be developed by being mindful of the nama or rupa appearing at the present moment. When there is mindfulness of one reality at the time understanding can investigate its characteristic and in that way it can gradually develop. When, for example, hardness appears there can be mindfulness of its characteristic and there is at that moment no thinking of a thing which is hard or of the place on our body where hardness impinges. If we think of the place of its impingement, such as a hand or a leg, there is an idea of "my body' to which we tend to cling. By being aware of one reality at a time we will lean that in the ultimate sense the body as a "whole" does not exist, that there are only different elements which arise and then fall away. 

     For the development of direct understanding of realities it is not enough to know only the specific characteristics of realities, the characteristics by which they are distinguished from one another. Understanding has to be developed stage by stage, so that it will be able to penetrate the three general characteristics of conditioned realities: the characteristics of impermanence, dukkha and non-self.

     When we are absorbed in concepts and there is no mindfulness, we live as in a dream and we do not know what is really there: only ever-changing namas and rupas. We read in the Middle Length Saying (II, no. 54, Discourse to Potaliya) that the Buddha painted out in different similes the dangers and disadvantages of sense pleasures. One of these similes is the following:

And, householder, it is as if a man might see in a dream delightful parks, delightful woods, delightful stretches of level ground and delightful lakes; but on waking up could see nothing. Even so, householder, an ariyan disciple reflects thus: "Pleasures of the senses have been likened by the Lord to a dream, of much pain, of much tribulation, wherein is more peril." And having seen this thus as it really is by means of perfect wisdom... the material things of the world are stopped entirely.

     When we learn that seeing only sees visible object we may have doubts about the characteristic of seeing. It seems that there is all the time paying attention to the shape and form of things or noticing the dimensions of things. This is thinking, not seeing, the experience of what appears through eyes. If there were no thinking one could not observe shape and form or dimensions of things. But such moments of thinking ate conditioned by seeing, by the experience of what appears through the eyes. There are also moments of just seeing, moments that we are not pairing attention to details or focusing on a "think". It is the same when we read a book. It seems that there are only moments of paying attention to the shape of the letters and their meaning, but there must also in between be moments of experiencing visible object, otherwise we could not read. Before we studied the Dhamma we never considered what seeing is, but if we lean to be mindful of one reality at a time understanding will know realities as they are. There is time and again thinning of concepts and then the reality of thinning can be object of mindfulness so that it will be known as non-self. Gradually we can lean to be mindful of seeing, visible object, hearing, sound and all the other realities which appear through six door in our daily life.

     Understanding is one of the wholesome faculties (indriyas), called the "spiritual faculties", which has to be developed together with the other "spiritual faculties" of confidence, energy, mindfulness and concentration. Through the development of these faculties the four noble Truths can be realized. Understanding is a controlling faculty, an indriya, in the sense Of predominance since it overcomes ignorance (Atthasalini I, Book I, Part IV, Chapter 1, 122) (1 See also Dhammasangani (Book I, chapter I, 6) which describes understanding among others as "searching the Dhamma", that is: the four noble truths, as a "guide", as a "sword" which cuts off defilements, as a "light", as "glory" or "splendour"), It exercises government over the associated dhammas (the citta and cetasikas it accompanies) by the characteristic of vision, that is, the realization of the three characteristics of impermanence, dukkha and anatta. The Atthasalini states further on (in the same section) that understanding has as characteristic illuminating and understanding. It states (123) that just as a clever surgeon knows which food is suitable and which is not, understanding knows states as "moral or immoral, serviceable or unserviceable, low or exalted, black or Pure..." Understanding which has been developed knows the four noble Truths.

The Atthasalini then gives another definition of understanding:

Understanding has the penetration of intrinsic nature, unfaltering penetration as its characteristic, like the penetration of an arrow shot by a skilled archer; illumination of the object as its function, as it were a lamp; non perplexity as its proximate cause, as it were a good guide in the forest.

     Understanding is also a " power" (bala), because it does not vacillate through ignorance (Atthasalini, I, Book I, Part IV, Chapter II, 148). As we have seen, when the wholesome faculties have been developed they become powers which are unshakeable. They cannot be shaken by their opposites.

     Right understanding of realities, samma-ditthi, is a factor of the Eightfold Path which has to be developed together with the other factors of the eightfold Path so that it can penetrate the four noble Truths. The object of right understanding which is not lokuttara, supramundane, but "lokiya", mundane, is the nama or rupa appearing at the present moment. The object of right understanding which is lokuttara is nibbana. Right understanding which accompanies the lokuttara magga-citta eradicates defilements; defilements are eradicated at different stages of enlightenment and all of them are eradicated at the attainment of arahatship.

     Understanding is classified in several ways and thus its different aspects can be seen. It has been classified as one of the seven factors of enlightenment (sambojjhangas) and as such it is called investigation of dhamma , dhamma vicaya. The factors of enlightenment are mindfulness, investigation of dhamma, energy, enthusiasm, calm, concentration and equanimity. These factors have to be developed together for the purpose of attaining enlightenment. There has to be "investigation" of the reality, the dhamma, appearing at the present moment, over and over again before enlightenment can be attained and defilements eradicated.

     Understanding which is supramundane, lokuttara, can be classified by way of three faculties: 

1) "I-shall-come-to-know-the-unknown" faculty (an-annatannassami 't' indriya), arising at the moment of the magga-citta of the sotapanna (1 Dhammasangani , 362-364. Vis. XIV, 3.).
2) The faculty of final knowledge (annindriya), which arises at the moment of the phala-citta, fruition-consciousness, of the sotapanna, and also accompanies the magga-citta and the phala-citta of the sakadagami and of the anagami and the magga-citta of the arahat (2 Dhammasangani , 505.).
3) The final knower faculty (annatavindriya), arising at the moment of the phala-citta of the arahat.

The sotapanna still has to develop right understanding of nama and rupa because his understanding has not reached the degree that all defilements can be eradicated. The task of developing understanding is finished only when the "final knower faculty" has arisen (3 Dhammasangani, 553.). 

     When we learn about the different classifications of understanding we can be reminded that understanding has to be developed in order to reach higher stages. It should be developed in whatever situation in our daily life we may be. We are inclined to think that awareness of the present moment is too difficult, but that one day in the future we may reach the goal. If we think that the present situation is not favourable for the development of right understanding, it will not develop. We should remember that each moment is in fact a new situation which is conditioned and which is beyond control, and that it is therefore useless to prefer another situation to the present one. We should not worry about the situation we are in but we should be mindful of whatever reality appears. There is for example time and again heat or cold. Usually we think of a concept of "I am hot" or "I am cold", but heat and cold are only rupa-elements and they can be objects of mindfulness when they appear. There is no self who experiences heat or cold, it is time which arises because of conditions. Through the development of understanding one will be less inclined to cling to a concept of "I feel" or "I experience". It is only a type of nama which experiences something, a nama which has arisen and then falls away immediately. There can be a beginning of understanding when there is mindfulness of what has already arisen at this moment because of its appropriate conditions.

I Why can there only be direct understanding of realities when there is mindfulness of them?
II Understanding is an indriya, a controlling faculty. What does it control?
III What is the object of right understanding of the eightfold Path which is mundane, not supramundane, lokuttara? 
IV We may find a particular situation too difficult, not favourable for the development of understanding. What should we do when we are in such a situation?