However, later in life there is the possibility of a re-integration with the dynamic ground, a trans-egoic stage. According to Washburn this transpersonal development requires a kind of U-turn, or going back to the dynamic ground, in order for the ego to become integrated with its unconscious dynamics. This aspect of Wasburn's model is described by commentators as «a going back before a higher going forth». A regression that paves the way for transcendence, and a fully embodied life. Washburn's approach to transpersonal development is often summed up as «regression in the service of transcendence» which, according to Lev, is a "twist of the phrase, regression in the service of the ego". Washburn has contrasted his own perspective, which he calls spiral-dynamic, to the developmental theory of Ken Wilber, which he calls structural-hierarchical. The differing views of Washburn and Wilber are mentioned by several commentators.