ABSTRACT
All physicists agree that the task of physics consists in tracing the phenomena of nature back to the simple laws of mechanics. But there is not the same agreement as to what these simple laws are. To most physicists they are simply Newton’s laws of motion. To most physicists they are simply Newton’s laws of motion. But in reality these latter laws only obtain their inner significance and their physical meaning through the tacit assumption that the forces of which they speak are of a simple nature and possess simple properties. In his important paper on the physical applications of dynamics, J. J. Thomson pursues a train of thought similar to that contained in von Helmholtz’s papers.
