Abhidhamma Pitaka
As the last major division of the canon, the Abhidhamma Pitaka has had a checkered history. It was not accepted as canonical by the Mahasanghika school and several other schools. Another school included most of the Khuddaka Nikaya within the Abhidhamma Pitaka. Also, the Pali version of the Abhidhamma is a strictly Theravada collection, and has little in common with the Abhidhamma works recognized by other Buddhist schools. The various Abhidhamma philosophies of the various early schools have no agreement on doctrine and belong to the period of 'Divided Buddhism' (as opposed to Undivided Buddhism). The earliest texts of the Pali Canon (the Sutta Nipata and parts of the Jataka), together with the first four (and early) Nikayas of the Suttapitaka, have no mention of (the texts of) the Abhidhamma Pitaka. The Abhidhamma is also not mentioned at the report of the First Buddhist Council, directly after the death of the Buddha. This report of the first council does mention the existence of the Vinaya and the five Nikayas (of the Suttapitaka).