“For the ego exists in an abstract sense alone, being an abstraction from memory, somewhat like the illusory circle of fire made by a whirling torch. We can, for example, imagine the path of a bird through the sky as a distinct line which it has taken. But this line is as abstract as a line of latitude. In concrete reality, the bird left no line, and, similarly, the past from which our ego is abstracted has entirely disappeared. Thus any attempt to cling to the ego or to make it an effective source of action is doomed to frustration.”