On the Nature of Movement in General

Abstract

Having to deal with the force and energy of the act of percussion, I will at first as shortly and as clearly as I can explain some notions concerning movement in general: what movement is, what its causes and its principles are, what its effects are, how it is provoked or stopped, and other points of this kind.

Firstly, as far as the definition of movement is concerned, it is known, as we described elsewhere, that a definition is a concept or an idea through which we perceive clearly the nature of the defined object and through which we distinguish and separate this object from anything else. We obtain the definition by selecting a property or a quality of this object which is the best known of all which belong to it. The most obvious characteristic of the bodies which are displaced or moved, and which is absent in all the bodies at rest and immobile is nothing else than their passage or migration from one place to another.