Different Kinds of Purity - 4th Purity
The fourth purity is Purity by overcoming doubt (kankhavitarana visuddhi).
When purity of view has arisen, panna developed through satipatthana sees
the characteristics of dhammas as they really are. Panna sees realities
as they are while sati is aware of the characteristics of realities as they
appear through the eyes, the ears, the nose, the tongue, the bodysense and
the mind-door. In that way panna becomes accomplished to the degree that
the second stage of insight can arise: knowledge of discerning conditions of
nama and rupa (paccaya-pariggaha-nana). When one directly understands
that realities arise because of their appropriate conditions, doubt about their
conditional arising is eliminated. Then there is the purity by overcoming
doubt.