Ignorance
Avijjā Sutta  (SN 45:1)

I have heard that on one occasion the Blessed One was staying near Sāvatthī in Jeta’s Grove, Anāthapiṇḍika’s monastery. There he addressed the monks, “Monks!”

“Yes, lord,” the monks responded to him.

The Blessed One said, “Monks, ignorance is the leader in the attainment of unskillful qualities, followed by lack of shame & lack of compunction. In an unknowledgeable person, immersed in ignorance, wrong view arises. In one of wrong view, wrong resolve arises. In one of wrong resolve, wrong speech.… In one of wrong speech, wrong action.… In one of wrong action, wrong livelihood.… In one of wrong livelihood, wrong effort.… In one of wrong effort, wrong mindfulness.… In one of wrong mindfulness, wrong concentration arises.

“Clear knowing is the leader in the attainment of skillful qualities, followed by shame & compunction. In a knowledgeable person, immersed in clear knowing, right view arises. In one of right view, right resolve arises. In one of right resolve, right speech.… In one of right speech, right action.… In one of right action, right livelihood.… In one of right livelihood, right effort.… In one of right effort, right mindfulness.… In one of right mindfulness, right concentration arises.”

See also: MN 117; AN 10:61; AN 10:103