A significant difference between the two manifestations of being is to be seen in the fact that only as a thing does the world have solidity and tangible durability. Only as It can the world be circumscribed by the coordinates of time and space. Being, however, as a personal presence, as Thou that meets us, does not endure in time, nor can it be placed in space beside another presence. The relation between I and Thou is only possible in the spontaneity of a timeless now. A meeting remembered is no longer the living relation. In memory, one’s former Thou has already become an It. In each encounter one meets only one presence at a time. The moment the I becomes aware of a new presence, one has brought an encounter to a close and entered into a new relation. The former Thou has now sunk down into the world of thinghood as a past experience. All presence exists for me in the actuality of my encounter with it. Without such actuality all reality turns for me into thinghood. All relations with one’s Thou are exclusive. The It borders on other Its; the Thou does not border. However, being that cannot be caught in the net of the time-space coordinates lacks solidity. Thus, the I-Thou aspect of reality is fleeting. One encounters one’s Thou unexpectedly and loses it again without warning. A Thou may reveal himself to one in a flash and will fade away again with equal speed. It is man’s melancholy lot that every Thou must turn for him into an It most of the time of his life.