Dynamics, or the theory of motion, is the science of the temporal passage of spatial events. At least this is how this study has come to be defined. But is it really true that we can arrive at a clear understanding of dynamics using this definition?

The naïve understanding is satisfied with this explanation. Indeed, what is so clear and simple as space and time? Space is what we see with our eyes, and time is what we feel as everything is passing by, one thing always after the other. But is this true? Who has ever seen space? I mean that one can only see objects in space and that they stand in the particular relations we call “in front of,” “behind,” “to the right of” and “to the left of.” We coordinate every object with a place in space; but to speak of the space itself, we then have to mentally extract all of the objects. That is a very broad abstraction. How do I know that this space exists when all bodies are removed? Not through experience, since all observations refer to those real things and their respective distances can only be defined with respect to the things around them. It is therefore a peculiar construction in which we embed things such that it is attached to them but can never be observed, and, unlike forces or heat that will make them glow, has no effect on them, yet it dictates far-reaching laws.