Qualities arise out of the properties of bodies when they are considered in relation to human purposes. To understand this declaration it is necessary to consider the essentials of properties and qualities and carefully to note the distinction between them. The essentials of the properties are unity, extension, speed, persistence, and consciousness, which, under relations, give rise to properties that can be measured. These properties are number, space, motion, time, and judgment.
Number is many in one, and the enumeration of the many is the measuring of the number contained in the sum which is a unity. Number, therefore, is many in one.
The second property is space; its essential is extension, but many extensions give rise to relative position, and the positions can be measured. Hence extension and position constitute space, and space is a property that can be measured.
Speed is the essential of motion, but the same particle in motion traverses a path. Motion, therefore, is speed and path,