Kenneth Earl Wilber, Jr. (b. January 31, 1949) is a contemporary writer and thinker whose primary focus is the development and exposition of an integral theory of consciousness. His first book, The Spectrum of Consciousness, sought to integrate a number of disparate fields, including metaphysics, psychology, spirituality, the natural sciences, the arts and humanities. 
Wilber is not widely recognized by mainstream academia, as he has not published in any recognized peer-reviewed journals, except for two articles that have appeared in the Journal of Consciousness Studies.  Defenders of his work suggest that his failure to publish in mainstream journals is a consequence of the meta-disciplinary and meta-theoretical nature of Integral Theory, which the highly specialized orientation of academic journals and the peer review process itself are not structured to support.
Critics of Wilber's work seem to agree that on the whole his efforts to develop and present an integrated theory of consciouness have been successful. The primary criticism appears to be more about Wilber's presentation, described as overly rational and an "attempt to make everything fit", than the content of his work. Criticisms of the work itself suggest that his overall position tends toward the excessively objectifying, masculinist, and denigrating of emotion.
William Irwin Thompson has suggested that Wilber’s approach suffers from a scheme of compulsive mapping and textbook categorizations. Steve McIntosh argues that Wilber’s theories are contaminated by his own investment in Vedanta and Buddhism, wherein he fails to separate those elements from philosophy as an objective area of study. McIntosh goes on to suggest that Wilber misinterprets Howard Gardner’s work in multiple intelligences,  while also failing to acknowledge Daniel Goleman’s differentiation between rational intelligence and emotional intelligence. 
Christian de Quincey, despite voicing an abiding respect for Wilber and his contributions to transpersonal psychology, evoked an acerbic response from Wilber when he suggested that Wilber’s theories were an intellectual edifice, details of which might fail under close scrutiny. 
- Wilber, K. (1973). The spectrum of consciousness. Quest Books: India.
- Journal of consciouness studies
- Gardner, H. (2006). Multiple intelligences: New horizons. Perseus Books Group: Boston.
- Goleman, D. (1998). Emotional intelligence. Bantam Books: New York.
- de Quincey, C. (2000). The promise of integralism: A critical appreciation of Ken Wilber's integral psychology. Journal of Consciousness Studies, Vol. 7(11/12)