The third division of the Pitakas. It consists of seven books: the
all designated by the name of Pakarana. Only in the Chronicles and the Commentaries is the word used as the title of a third Pitaka (See the discussion of this in DA.i.15, 18f). In the Canon itself (E.g., Vin.i.64; iii.144; iv.344) the word means "special dhamma," i.e. the Doctrine pure and simple (without admixture of literary treatment or personalities, etc.), and is sometimes coupled with the word abhivinaya (E.g., D.iii.267; M.i.272).
It has been suggested (New Pāli Dict. s.v.) that, as the word abhidhamma standing alone is not found either in the Sutta Nipāta, the Samyutta, or the Anguttara, and only once or twice in the Digha and Majjhima, it probably came into use only towards the end of the period in which the four great Nikāyas grew up (See Dial.iii.199 on a possible origin of the Adhidhamma).
The Mahāsanghikas refused to include the Abhidhamma in the Pitakas at all, as they did not regard it as the word of the Buddha. (Dpv.v.32-8).
According to the Dighabhānakas the Abhidhamma Pitaka also included the whole of the Khuddaka Nikāya except the Cariyāpitaka, Apadāna and Buddhavamsa (DA.i.15).
According to another division, the five Nikāyas are not divisions of the Dhamma but of the whole Canon, and in the fifth are included both the Vinaya and the Abhidhamma (DA.i.28).
There is a legend recorded by Buddhaghosa that the Abhidhamma was first preached by the Buddha in Tāvatimsa at the foot of the Pāricchataka tree, when he was seated on Sakka's throne, during his visit to his mother in Tāvatimsa. Later it was taught by him to Sāriputta on the banks of the Anotatta Lake, whither Sāriputta had gone to minister to the Buddha during the latter's visit to Tāvatimsa (VibhA. p.1; AA.i.71, etc.).
The legend further relates that after the Enlightenment the Buddha spent the fourth week in the Ratanaghara, revolving in his mind the intricate doctrines of the Abhidhamma in all their details (J.i.78).
According to the Cullavagga version of the Councils (Chaps. xi. and xii; but see DA.i.15 contra) the Abhidhamma Pitaka was not rehearsed at either Council.
The fact that the Abhidhamma is not mentioned in the suttas and that only Dhamma and Vinaya are usually referred to, only proves that at one time the Abhidhamma did not form a separate Pitaka. As a matter of fact, it is not held even by the commentators to be the word of the Buddha in the same sense as the suttas. One section of it, the Kathāvatthu (but see Kathāvatthu), was taught only at the Third Council.
As far as we know, the seven books of the Abhidhamma are peculiar to the Theravādins, though there is evidence that other schools, chiefly the Vaibhāsikas (Sarvāstivādins) and the Sautrāntikas, held the Abhidhamma books sacred. See Tārānātha: Geschichte des Buddhismus (56) 156 (296).
As far as the contents of the Abhidhamma are concerned, they do not form a systematic philosophy, but are a special treatment of the Dhamma as found in the Sutta-Pitaka. Most of the matter is psychological and logical; the fundamental doctrines mentioned or discussed are those already propounded in the suttas and, therefore, taken for granted. For a discussion of the contents see article on Abhidhamma in ERE.
Apart from the Commentaries on the seven books, an exegetical work on the whole Pitaka, called the Abhidhamma Mūlatīkā, was written by Ananda Vanaratanatissa of the Vanavāsī school in Ceylon.
The Tīkā was evidently based on Buddhaghosa's Commentaries, but Ananda occasionally dissents from Buddhaghosa. The work was written at the request of an Elder, Buddhamitta, and was revised by Mahā Kassapa of Pulatthipura.
An Anutīkā was written by Culla Dhammapāla. Gv.60, 69. For details see P.L.C., pp. 210-12. The Gv. (72) also mentions Abhidhammagandhi, probably a glossary.