Every experience can be made intelligible by contrast. If there were no straight line, we could not say high and low, right and left; it is the straight line which makes us recognize them as such. If there were no sun we would not be able to say south, north, east and west. Therefore with every conception there must be some object to focus upon which helps to form our conception. In order to understand deep sleep we have nothing in the physical existence to compare it with and therefore that experience of deep sleep remains only as a great satisfaction, joy and upliftment, as something that has vitalized us and has created energy and enthusiasm in life. This shows that there is something we receive; we do not come empty-handed from there, we have attained something we cannot get here from the physical plane. From there we receive something that we cannot interpret in everyday language-more precious, more valuable and vital than anything from the physical and mental planes.