The Newtonian Physics of Billiard Balls

Newtonian physics of billiard balls is essentially time symmetric. But we don't have the direction of causation going the other way, nothing in the future could affect what has already happened. So where is our sense that the causation is running forwards actually coming from? That was Russell's question. Well my best guess was it's coming from our sense of what time is - things happen before and after each other so time moves in one particular direction. We can imagine creatures who are living somewhere else in the universe who have the opposite orientation to us. And there isn't any objective sense in which one of us is right and the other is wrong.