as analogies go , that is a pretty good analogy of what i have done ; you can understand now a little of what i felt as i stood here one evening ; it was a summer evening , and the valley looked much as it does now ; i stood here , and saw before me the unutterable , the unthinkable gulf that yawns profound between two worlds , the world of matter and the world of spirit ; i saw the great empty deep stretch dim before me , and in that instant a bridge of light leapt from the earth to the unknown shore , and the abyss was spanned .