Since I am launched into the open sea and I have given my full sails to the wind, nothing in all the world remains unchanged. All things are in a state of flux, all shapes receive a changing nature. Time itself glides on with constant motion, ever as a flowing river. Neither river nor the fleeting hour can stop its constant course. But, as each wave drives on a wave, as each is pressed by that which follows, and must press on that before it, so the moments fly, and others follow, so they are renewed. The moment which moved on before is past, and that which was not, now exists in Time, and every one comes, goes, and is replaced.
Ovid, Metamorphoses 15, section 176.
Via The Useless Tree.