To put it simply, Wilber's thesis is that humanity is following a path of evolution upwards through a series of "structures of consciousness", beginning with primitive mental states, then progressing through more complex psychological structures, before eventually venturing into the "transpersonal", the higher states of consciousness previously experienced only by sages and mystics. Each of these stages of internal awareness, according to Wilber, correlates with the type of social organisation that the individual lives within. Wilber argues that as a society evolves through various stages, the consciousness of its members evolves with it, giving us a schema of development as follows:
|Society||Structure of Consciousness|
While it is not my intention here to critique this model, it is immediately obvious that one problem with it is that Wilber has never attempted to describe the types of social organisation that correlate with each of the transpersonal stages. Indeed, it would appear that after the emergence of a world government, no further development is possible.
However, a more serious issue, in my opinion, is that Wilber takes it as given that collective development proceeds through the progressive centralisation of power. Yet to me this is far from obvious. In a series of essays available in the Reading Room of Integral World (http://www.integralworld.net/readingroom.html#JO) I argue that healthy social development actually proceeds through the progressive decentralisation of power, although I should say that my current thinking is that a middle way between centralisation and decenentralistion is the desired course. In my papers I have attempted to show that when we base our schema of development on such a premise, we end up with a model that is more coherent than is Wilber's, and which avoids many of the problems inherent in his approach.
A more seriously problem, in my opinion, is that to anyone who accepts the existence of a global conspiracy - the agenda to impose an authoritarian one-world government on the planet - Wilber's model could be seen as dangerously rationalising such a state of affairs. In fact one implication of Wilber's schema is that the emergence of a world government would positively further our collective evolution. Wilber could therefore be quite unintentionally leading his readers into the "new world order" that is the goal of the global conspiracy. Indeed, some of Wilber's followers are already openly calling for world government.
It should therefore come as no suprise to followers of global-conspiracy research that individuals such as Bill Clinton and Al Gore have lauded Wilber's work (http://www.kenwilber.com/blog/show/543). According to David Icke, Clinton and Gore are both front-men for the global conspiracy, and have been promoting the new world order agenda since they were in office.
Wilber clearly believes that his work is at the forefront of human evolution and has recently started a movement to promote his views (https://www.integrallife.com/), yet as the hundreds of critical essays available at Integral World demonstrate, his work is not as watertight as he would like us to believe.
While there is much to be said for any big picture model of reality that includes a spiritual dimension, I believe that in the age of the global conspiracy we need to be very wary of any paradigm that views a world government as representing a positive evolutionary advance.