The third division of the Tipiṭaka. It consists of seven books: the:-
All are designated by the name of Pakaraṇa. Only in the Chronicles and the Commentaries is the word used as the title of a third Piṭaka (See the discussion of this in DA.i.15, 18 f). 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 Pāḷi Dict. s.v.) that, as the word abhidhamma standing alone is not found either in the Suttanipāta, the Saṃyuttanikāya, or the Aṅguttaranikāya, and only once or twice in the Dīghanikāya and Majjhimanikāya, 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 Abhidhamma).
The Mahāsaṅghikas refused to include the Abhidhamma in the Piṭakas at all, as they did not regard it as the word of the Buddha. (Dpv.v.32‑8).
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 Piṭaka and the Abhidhamma (DA.i.28).
There is a legend recorded by Buddhaghosa that the Abhidhamma was first taught by the Buddha in Tāvatiṃsa at the foot of the Pāricchataka tree, when he was seated on Sakka’s throne, during his visit to his mother in Tāvatiṃsa. Later it was taught by him to Sāriputta on the banks of the Anotatta Lake, to where Sāriputta had gone to minister to the Buddha during the latter’s visit to Tāvatiṃsa (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 Cūḷavagga version of the Councils (Chaps. xi. and xii; but see DA.i.15 contra) the Abhidhamma Piṭaka 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 Piṭaka. 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 Piṭaka. 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 Piṭaka, called the Abhidhamma Mūlaṭīkā, was written by Ānanda Vanaratanatissa of the Vanavāsī school in Sri Lanka.
The Ṭīkā was evidently based on Buddhaghosa’s Commentaries, but Ānanda occasionally dissents from Buddhaghosa. The work was written at the request of an elder, Buddhamitta, and was revised by Mahā-
An Anuṭīkā was written by Cūḷa Dhammapāla. Gv.60, 69. For details see P.L.C., pp.210‑12. The Gv. (72) also mentions Abhidhammagandhi, probably a glossary.