Consequently our conceptions of physical reality can never be final. We must always be ready to change these conceptions, i.e. the axiomatic basis of physics, in order to do justice to the facts of observation in the most complete way that is logically possible. In actual fact, a glance at the development of physics shows that this axiomatic basis has met with radical changes from time to time. The greatest change in the axiomatic basis of physics, and correspondingly in our conception of the structure of reality, since the foundation of theoretical physics through Newton, came about through the researches of Faraday and Maxwell on electromagnetic phenomena. In what follows we shall try to present this in a more precise way, while taking the earlier and later development into account.
Physical events are to be thought of as movements according to law of material points in space.
The material point is the only representative of reality in so far as it is subject to change. The material bodies which had psychologically given rise to the formation of the concept of 'material point' had now for their part to be conceived as a system of material points. It is to be noted that this theoretical system is essentially atomistic and mechanistic. All happening was to be conceived of as purely mechanical, that is, merely as motions of material points according to Newton's laws of motion. Moreover, it is altogether unsatisfactory to introduce into the discussion two quite different kinds of material points which had to be put forward to represent ponderable matter and light.