The last book of the Abhidharma Piṭaka of the Pāli Canon. The book is divided into two parts, the Tika-paṭṭhāna dealing with ‘groups of three’ and the Duka-paṭṭhāna.dealing with ‘groups of two’. The work can be described as the ‘book of causes’ in that it deals with the 24 modes of relations (paccaya) between things, mental and material. It is a highly technical text, giving a minutely detailed analysis of the doctrine of conditionality or Dependent Origination (pratītya-samutpāda). Its commentary was compiled by Buddhaghoṣa in the 5th century.