(2015, Arp et. al., Building Ontologies with Basic Formal Ontology, MIT Press)
**1."Provide all non root terms with definitions."**
"An ontology is a semantic artifact—it has to do with regimenting terms in such a way that they will be associated with specific meanings, and for this purpose the ontology must provide definitions."
**2."Use Aristotelian definitions."**
An Aristotelian definition follows this form: **S = def. a G that Ds**,
where “G” (for: genus) is the immediate parent term of “S” (for: species) in the ontology for which the definition is being created. “D” stands for differentia, which is to say: “D” tells us what it is about certain Gs in virtue of which they are Ss. Ideally, the terms used in formulating the differentia D will themselves be terms taken from some ontology, where they will themselves be defined.
Consider, as a first example, Aristotle’s own definition of “human”:
