The idea is clear enough. The self experienced as piloting its way through a world, together with that world and the vessel that makes it possible are all together the objects of a witnessing awareness that is brought to centrality by allowing the pilot and his ship and his very ocean to fall backwards into a very deep hole normally hidden somewhere behind his phenomenal eyes. From here the field of experience is flattened out and its chief folds or pivot-lines along which the material and spatio-temporal distinctions of the physical world are created and sustained are seen a phenomena on equal terms with all others. A duality reigns now, but it is a simple one of seer and seen, of spirit and matter now understood as perfectly correlative. But if the objective field has been emptied of being a sense of being remains in the subjective until it is realised that this witness cannot be distinct from what it is witnessing. So now it dissolves too into an ineffable unity prior to all experience. In each case it is a matter of achieving a certain rotation of the structure of knowing. Every level of consciousness is simply a closed group of rotations and each transition between levels is the discovery that the very same structure can rotate in the most natural way in a further unsuspected direction. You cannot suspect the address of such a rotation until you have made it.