Energy. Various hermitage ordeals helped David to free his thoughts from ego chatter and enter into deep silence, wherever he finally experienced Enlightenment. Collecting a couple of passages from ACOL and presenting them side by aspect with ACIM’s prices that evidently contradict them don't establish that the texts are incompatible, https://www.youtube.com/channel/UCTleG6-484F7WHZD0hAjRRw