"Our existence has no foundation to support it except the ever-fleeting and vanishing present; and so constant motion is essentially its form, without any possibility of that rest for which we are always longing. We resemble a man running down hill who would inevitably fall if he tried to stop, and who keeps on his legs only by continuing to run; or we are like a stick balanced on a finger tip; or the planet that would fall into its sun if it ceased to hurry forward irresistibly. Thus restlessness is the original form of existence."