Roberto Mangabeira Unger
The Self Awakened

Pragmatism Unbound
Harvard University Press 2007

3 Unger The Self Awakened 3
10 The Perennial Philosophy: In the world history of philosophy there has been a dominant view: in fact, so dominant that it alone deserves a label coined by Leibniz - the perennial philosophy.
A single doctrine about difference and being has prevailed in the world history of thought. According to this hegemonic view, the manifest world of distinction and change is an illusion, or if not simply an illusion, then a shallow and ephemeral expression of a more real unity of being.
The manifold within which everything seems to be what it is and to be different from everything else is not the ultimate reality. The illusionary character of the superficial nature of difference in the manifold applies as well to the differences of greatest and most urgent significance to us: the differences among persons. The perennial philosophy dismisses these differences as misleading.
Ultimate reality is a single force - energy, spirit, being - that appears to us under the disguise of division, difference, and distinction. However, such separations, culminating in the individuality of persons, are - if not illusionary - epiphenomenal. They report how we ordinarily meet and perceive the world, not how the world really is. At best, they are transitory and superficial. They fail to cut down to the roots of being.
Insofar as we represent the world in the form of this differentiated manifold, we do not grasp it for what it ultimately is: a unity prior to all difference.