The three knowledges (tevijja) are the insights that emerge just prior to enlightenment and which in the case of the last, is one of the prerequisites of the enlightenment experience. The first is the knowledge of past lives (pubbe nivàsànussati ¤àõàya) wherein one sees with great clarity and in detail the long parade of one's former lives. This dramatic experience allows one to verify the truth of rebirth from direct experience. The second is the knowledge of the arising and passing away of beings according to their kamma (satànaü cutåpapàta ¤àõàya). With this knowledge one understands the complex and subtle workings of kamma. The Buddha said that while an ordinary person may believe in and accept the reality of kamma, only an enlightened person actually has a personal and direct knowledge of its operation (A.III,348 ff).        

The third and most important is the knowledge of the destruction of the mental defilements (àsavànaükhaya ¤àõàya, D.I,81-3); sensual desire, desire for continued existence, ignorance and originating.  The arising of and access to the three knowledges  becomes possible only  when the mind is `focused and purified, cleansed and unblemished, pliant and free of defilements, malleable, stable, firm and imperturbable'.     The Buddha  also says that  access to these knowledges  requires one to `turn and direct the mind' to them (cittaü abhinãharati abhininnàmeti);  in other words, by a conscious act of will (D.I,76).

In Brahmanism, a priest who has mastered the three Vedas (A.I,166; D.I,88) was said to have a threefold knowledge, in Sanskrit trayãvidyà. The Buddha used the same term for his knowledges, thus presenting them as alternative accomplishments that were higher and more important that the Brahmanical one, and that was accessible to all, not just to the highest caste.