What should we think about Wilber's method?

Ken Wilber's book Sex, Ecology, Spirituality is a work of enormous scope, which seriously attempts to integrate the major fields of human knowledge. This article focuses on Wilber's methodology, which consists of (a) a phenomenology of all human knowledge conducted at the level of orienting generalizations, (b) selection of the coherent system that incorporates the greatest number of orienting generalizations, and (c) critique of less encompassing systems.