Existence is play. Communication is play. You throw a ball of
   words "out here". I caught the ball (read your words) and I'm
   throwing it back to you (responding). To me, you exist, because
   the ball came from someplace and arrived into my eyes. I threw
   the ball at somewhere. I can't guarantee that I will be
   understood (that anybody will catch the ball) but I knew someone
   threw it at me, and I threw it back. Therefore, to me, you exist
   as the thrower of the ball.