A THEORY OF PROPERTIES AND KINDS
MARIO BUNGE, Arturo A. L. Sangalli · International Journal of General Systems · 1977
All things possess properties, and the properties of interest are represented by attributes or predicates. The latter are well known objects, as they are elucidated and systematized by predicate logic and the theory of functions. On the other hand the notion of a property possessed by a concrete thing is still obscure for want of a theory. So is the notion of a kind as different from that of an arbitrary set The present paper presents a mathematical theory of thing properties and applies it to the construction of a theory of kinds of thing. The theory employs three basic concepts: those of concrete individual, concrete property, and scope of a property. The notions of precedence, equivalence, conjunction, and compatibility of properties are defined. Several theorems are proved. In particular, it is shown that the set of all general properties is a sup-semi-lattice (not a Boolean algebra), and that the family of all kinds has the lattice structure.