The Abhidhamma Pitaka (abhidhammapitaka) is the last of the three pitakas ( Pali for "baskets") constituting the Pali Canon. Abhidhamma Pitaka provides a theoretical framework to explain the causal underpinnings of that very path. In Abhidhamma philosophy the familiar psycho-physical universe (our world of "trees" and "rocks," "I" and "you") is distilled to its essence: an intricate web of impersonal phenomena and processes unfolding at an inconceivably rapid pace from moment to moment, according to precisely defined natural laws.
The Abhidhamma is useful to those who want to understand the Dharma in greater depth and detail. It aids the development of insight into the three characteristics of existence - impermanence, dissatisfactoriness, and non-self. Understanding the Dharma through the knowledge gained from the Sutra is like the knowledge acquired from studying the prescriptions for different types of sicknesses. Such knowledge when applied can certainly help to cure certain types of sicknesses. On the other hand, a qualified physician, with his precise knowledge, can diagnose a wider range of sicknesses and discover their causes. The Abhidhamma doctrine gives a clear exposition of the ultimate nature of man and brings the analysis of the human condition further than other studies known to man.
The Abhidhamma deals with realities existing in the ultimate sense, or paramattha dharma in Pali. There are four such realities:
Citta, mind or consciousness, defined as 'that which knows or experiences' an object. Citta occurs as distinct momentary states of consciousness.
Cetasika, the mental factors that arise and occur along with the citta.
Rupa, physical phenomenon or material form.
Nirvana, the unconditioned state of bliss which is the final goal.
Citta, the cetasika, and rupa are conditioned realities. They arise because of conditions, and will disappear when the conditions sustaining them cease to continue to do so. They are impermanent states. Nirvana, on the other hand, is an unconditioned reality. It does not arise and, therefore, does not fall away. These four realities can be experienced regardless of the names we may choose to give them. Other than these realities, everything - be it within ourselves or without, whether in the past, present or future, whether coarse or subtle, low or lofty, far or near - is a concept and not an ultimate reality.
Citta, cetisaka, and Nirvana are also called nama. Nirvana is an unconditioned nama. The two conditioned nama, that is, cita and cetasik, together with rupa (form), make up psychophysical organisms, including human beings. Both mind and matter, or nama-rupa, are analysed in Abhidhamma as through under a microscope. Events connected with the process of birth and death are explained in detail. The Abhidhamma clarifies intricate points of the Dharma and enables the arising of an understanding of reality, thereby setting forth in clear terms of an understanding of reality, thereby setting forth in clear terms the Path of Emancipation. The realization we gain from the Abhidhamma with regard to our lives and the world is not in a conventional sense, but absolute reality.
Abhidhamma and Modern Psychology
The clear exposition of thought processes in Abhidhamma cannot be found in any other psychological treatise either in the east or west. Consciousness is defined, while thoughts are analysed and classified mainly from an ethical standpoint. The composition of each type of consciousness is set forth in detail. The fact that consciousness flows like a stream, a view propounded by psychologists flows like a stream, a view propounded by psychologists like William James, becomes extremely clear to one who understands the Abhidhamma. In addition, a student of Abhidhamma can fully comprehend the Anatta (No-soul) doctrine, which is important both from a philosophical and ethical standpoint.
The Abhidhamma explains the process of rebirth in various planes after the occurrence of death without anything to pass from one life to another. this explanation provides support to the doctrine of Kamma and Rebirth. It also gives a wealth of details about the mind, as well as the units of mental and material forces, properties of matter, sources of matter, relationship of mind and matter.
In the Abhidhammatta Sangaha, a manual of Abhidhamma, there is a brief exposition of the Law of Dependent Origination, followed by a descriptive account of the Causal Relations which finds no parallel in any other study of the human condition anywhere else in the world. Because of its analytical and profound expositions, the Abhidhamma is not a subject of fleeting interest designed for the superficial reader.
To what extent can we compare modern psychology with the analysis provided in the Abhidhamma? Modern psychology, limited as it is, comes within the scope of Abhidhamma in so far as it deals with the mind - with thoughts, though processes, and mental states. The difference lies in the fact that Abhidhamma does not accept the concept of a psyche or a soul.
The analysis of the nature of the mind given in the Abhidhamma is not available through any other source. Even modern psychologists are very much in the dark with regards to subjects like mental impulses or mental beats (Javana Citta) as discussed in the Abhidhamma.
Abhidhamma essential for Dharma practice
Actually the essence, fundamentals and framework of the Abhidhamma are ascribed to the Buddha, although the tabulations and classifications may have been the work of later disciples. What is important is the essence. It is this that we would try to experience for ourselves. The Buddha himself clearly took this stand of using the knowledge of the Abhidhamma to clarify many existing psychological, metaphysical and philosophical problems. Mere intellectual quibbling about whether the Buddha taught the Abhidhamma or not will not help us to understand reality.
The question is also raised whether the Abhidhamma is essential for Dharma practice. The answer to this will depend on the individual who undertakes the practice. People vary in their levels of understanding, their temperaments and spiritual development. Ideally, all the different spiritual faculties should be harmonized, but some people are quite contented with devotional practices based on faith, while others are keen on developing penetrative insight. The Abhidhamma is most useful to those who want to understand the Dharma in greater depth and detail. It aids the development of insight into the three characteristics of existence - impermanence, dissatisfactoriness, and non-self. It is useful not only for the periods devoted to formal meditation, but also during the rest of the day when we are engaged in various mundane chores. We derive great benefit from the study of the Abhidhamma when we experience absolute reality. In addition, a comprehensive knowledge of the Abhidhamma is useful for those engaged in teaching and explaining the Dharma.
The Abhidhamma Pitaka is divided into seven books, although it is the first (Dhammasangani) and last (Patthana) that together lay out the essence of Abhidhamma philosophy. The seven books are:
I. Dhammasangani ("Enumeration of Phenomena").
II. Vibhanga ("The Book of Treatises").
III. Dhatukatha ("Discussion with Reference to the Elements").
IV. Puggalapaññatti ("Description of Individuals").
V. Kathavatthu ("Points of Controversy").
VI. Yamaka ("The Book of Pairs").
VII. Patthana ("The Book of Relations").
The Abhidhamma Pitaka has a well-deserved reputation for being dense and difficult reading. The best way to begin studying Abhidhamma is not to dive right into its two key books (Dhammasangani and Patthana), but to explore some of the more modern — and readable — commentarial texts. These will help you get oriented to the Abhidhamma's challenging terrain