The secret of happiness is hidden under the veil of spiritual knowledge. And spiritual knowledge is nothing but this: that there is a constant longing in the heart of man to have something of its origin, to experience something of its original state, the state of peace and joy which has been disturbed, and yet is sought after throughout its whole life, and never can cease to be sought after until the real source has at length been realized. What was it in the wilderness that gave peace and joy? What was it that came to us in the forest, the solitude? In either case it was nothing else but the depth of our own life, which is silent like the depths of the great sea, so silent and still. It is the surface of the sea that makes waves and roaring breakers; the depth is silent. So the depth of our own being is silent also.