The student who follows my argument must first become accustomed to the discrimination between concomitancy and relativity. Relativity is the relation of one particle or body to another; concomitancy is the coexistence of one property with another in the same particle or body.
Having deduced or discovered four essentials or concomitants in every particle of matter, we have yet to determine whether these are all, and for this purpose we are compelled to assemble in a passing review all of the bodies of the universe. To do this it becomes necessary to discover in what manner these four essentials become properties as quantities and kinds, for we have quantitative properties and classific properties. Having discovered how the essentials become properties, we can then go on in the review of the universe of bodies.
