Via Art Lindsley in Christianity Today, C.S. Lewis on "Progress":
We all want progress, but progress means getting nearer to the place you want to be and if you have taken a wrong turning, then to go forward does not get you any nearer. If you are on the wrong road, progress means doing an about-turn and walking back to the right road; and in that case, the man who turns back soonest is the most progressive man. We have all seen this when we do arithmetic. When I have started a sum the wrong way, the sooner I admit this and go back and start over again, the faster I shall get on. There is nothing progressive about being pigheaded and refusing to admit a mistake. And I think if you look at the present state of the world, it is pretty plain that humanity has been making some big mistakes. We are on the wrong road. And if that is so, we must go back. Going back is the quickest way on. (Mere Christianity)