Ontology 101

Ontology illustration

BFO+

stasis

process profile

capability

system

realism

Top-Level Ontology and hub-spokes approach

universal / instance

singular nouns

mass nouns

GDC, ICE

dependence

dispositions and qualities

capabilities and functions

roles

the all-some rule

single inheritance

the Aristotle definition of substance rule

the universal quantification rule (why you can't say 'Tylenol pill' is a 'pill which cures headache')

the no-multiple-inheritance rule (asserted vs. inferred)

Ontology Pitfall Scanner: https://oops.linkeddata.es/catalogue.jsp

Definitions and axioms in first-order logic must be kept separate from each other: the definition of a term x is designed to be the shortest and logically simplest specification of necessary and sufficient conditions for being and instance of x. The axioms specify additional distinguishing marks which are seen as holding for all such instances. The advantages of this strategy are: 1. definitions are easy to understand and easy to apply, 2. definitions are more stable in the sense that new kinds of x might be discovered, or might evolve, which falsify one or other axiom, but still satisfy the definition.