r meaning, like change. The word change would give us a full picture of the word motus; change of quality, like when the hot body becomes cold, change of quantity, like with an object increasing in size, and change of place, like local motion. Knowing this we can understand the fact that various things in our world are moved. But whatever is moved is moved by something else. To justify this, Thomas reasons that to be moved is to be reduced from potentiality to actuality. Nothing can then have to be in potency and in act in the same time and in the same respect. Whatever is moved, therefore, must be moved by something else. One can not regress to infinity with moved movers. If you have an infinite series of moved movers, you have an infinite number of bodies in motion whenever one of the series is in motion. “But any one of them, being finite, is in motion for finite time. Therefore all these infinite bodies are in motion for finite time. This is impossible.”Aquinas argues that one body can move another only if it is in contact with it, so all these contiguous moving and moved bodies make one large body, which is not infinite. This body would have to travel infinite distance in finite time; which is impossible. There we have it, we can not form infinite chain of moving and moved bodies, which leads us to the idea of the ultimate beginning which is not an infinity away.This might stand well with Aristotelian mechanics, but what about Newton and his laws? I would argue than, that the more we know about the universe, then with higher level of certainty we can say, everything in our world is affected (moved or changed) by something else (being moved by a mover). Einstein brought his theory of relativity to this world. Knowing it we can say that an X can be at rest relative to Y, but X at the same time can be moved by Y relative to Z. For example a rock which is on the surface of the earth in relation to the sun. Wh...
