Sri Aurobindo:
The world exists as symbol of Brahman; but the mind creates or accepts false values of things and takes symbol for essential reality. This is ignorance or cosmic illusion, the mistake of the mind & senses, from which the Magician Himself, Master of the Illusion, is calling on us to escape.
...the whole of universal existence is in this sense an illusion of Maya that it is not an unchanging transcendent and final reality of things but only a symbolical reality; it is a valuation of the reality of Brahman in the terms of cosmic consciousness. All these objects we see or are mentally aware of as objectively existing, are only forms of consciousness. They are the thing in-itself turned first into terms & ideas born of a movement or rhythmic process of consciousness and then objectivised, in consciousness itself and not really external to it. They have therefore a fixed conventional reality, but not an eternally durable essential reality; they are symbols, not altogether the thing symbolised, means of knowledge, not altogether the thing known.
Existence or Brahman has two fundamental states of consciousness, cosmic consciousness and transcendental consciousness. To cosmic consciousness the world is real as a direct first term expressing the inexpressible; to transcendental consciousness the world is only a secondary & indirect term expressing the inexpressible. When I have the cosmic consciousness, I see the world as my Self manifested; in transcendental consciousness I see the world not as the manifestation of my Self but as a manifestation of something I choose to be to my Self-consciousness. It is a conventional term expressing me which does not bind me; I could dissolve it and express myself otherwise.