External life is the shadow of the inner reality.
Bowl of Saki, August 6, by Hazrat Inayat Khan
Commentary by Hazrat Inayat Khan:
The outer manifestations of life are so rigid and dense that the secret of their nature and character is buried underneath. Why is the world called an illusion by the mystics? Because the nature of manifestation is such that it envelops its own secret within itself, and appears in such a rigid form that the fineness, beauty and mystery of its character are hidden. Therefore the seekers after the truth of life, the students of life, are of two opposite kinds. The one wishes to learn from outward appearance. The other wishes to find out the secret that is hidden behind it. The one who learns from the external gets the knowledge from the external, which we call science. The one who finds out from the within, from what is hidden in this manifestation, is the mystic. The knowledge he gains is mysticism ... Every activity of the outer world is a kind of reaction; in other words a shadow of the activity which is behind it and which we do not see.