**The Basic Formal Ontology Ontology **
BFO is the ‘Basic Formal Ontology ’, which is an upper-level (domain-independent) ontology for scaffolding out lower-level (domain-specific) ontologies. There are multiple domain-specific ontologies that are extensions of the BFO (e.g. - the information artifact ontology). The BFO is documented in the spec & the OWL language.
It’s a hierarchy. The top-level split is a breakdown into a thing that exist and endures (a “Continuant“) and a thing that happens (an “Occurent”). This is basically the “Objects” and “Processes” from OPM.
Entities
An entity is anything that can exist. It can be divided into instances (my heart, your heart), and universals (’heart’ in general). The BFO spec uses italics when referencing to universals.
Is_A Overloading
The BFO uses a much more strict and narrow definition of “Is_A” than our standard usage in English might allow. In BFO vernacular, “X Is_A Y” strictly means X is a subtype of Y. Not X is an instance of Y.
Determinables and Determinates
The BFO calls numeric measurements “Determinates” and their ancestors “Determinables”. So, “5lbs weight” is a determinate and “mass” is the determinable.
Notes Note.
There’s much more I could write about, but then I’d have to read it. This is not a universal truth, it’s an instance of how a group of folks decided to carve up describing the world.