According to both Bronkhorst and Anderson, the four truths became a substitution for prajna, or "liberating insight", in the suttas in those texts where "liberating insight" was preceded by the four jhanas. According to Bronkhorst, the four truths may not have been formulated in earliest Buddhism, and did not serve in earliest Buddhism as a description of "liberating insight". Gotama's teachings may have been personal, "adjusted to the need of each person."

Authors Bronkhorst and Anderson claim the four truths bacame a substitution for what?