Ken Wilber is one of the most important philosophers in the world today. He is the most widely translated academic writer in America, with 25 books translated into some 30 foreign languages. Wilber's philosophy has been influenced by Madhyamaka Buddhism, particularly as articulated in the philosophy of Nagarjuna. His integral approach gained popularity with the publication of his first book, The Spectrum of Consciousness, a synthesis of religion, philosophy, physics, and psychology which became the basis for all subsequent attempts at integrating psychology and spirituality. He supports the need for an integrated approach because in our current post-modern world, we possess an abundance of methodologies and practices belonging to a multitude of fields and knowledge traditions. In one of his most significant works, Sex, Ecology, Spirituality, in 1995, he introduced his iconic quadrant model often referred to as the AQAL model, with AQAL standing for all quadrants, all levels, all lines, all states, and all types. These five elements signify some of the most basic repeating patterns of reality. Integral Theory is widely ignored at mainstream academic institutions.