‘Visuddhimagga’ or ‘The Path of Purity’, is among the most important scholarly works of Theravada Buddhism and, indeed, of the whole Buddhist tradition. It contains a survey of the main teachings of the historical Buddha, while also preserving some of the earliest commentaries on the Pali Canon. Written by the scholar monk Buddhaghosa in the 5th century CE, it is divided into three distinct sections, Part 1: Of Virtue, Part 2: Of Concentration, Part 3: Of Understanding. The author’s achievement can be seen by the fact that it has remained a comprehensive and trustworthy guide to the Buddhist path down to the present day. The Pali Canon, the oldest source we have for the Buddha’s teachings in his own words, was only written down in Pali in the first century BCE following centuries of purely oral transmission.