 Leibniz also argues in this way: If the mind (one finite substance) were to act on the body (another finite substance) thereby causing bodily motion, there would be an increase in motion in that region of the world after the mind’s action on the body not compensated for by a decrease in motion in another region. This is an obvious violation of the law of the conservation of motion. Therefore, there is no physical influx. The Monadology includes the following passage: