Giorgio Lando

are formal features enough to isolate a subject matter? In the specific case of parthood, the answer seems to be: no, they are not enough. There are also intuitive constraints on what counts as parthood.

Formal features allow for a discrimination within an already limited domain of relations that have something to do with containment and being in.

The formal constraints, inspired by prototypical, spatial cases of literal parthood, allow us to discriminate genuine relations of parthood within this intuitively constrained domain.

The formal features of parthood and of other cognate relations and operations are what philosophical mereology is about. These formal features are necessary conditions for being a genuine parthood relation. They are not sufficient conditions, because the domain of eligible relations is constrained by an intuitive condition.

Mereology is about nonselective parthood; selective notions of parthood (often expressed by cognate terms such as “component” in (e)) are not its subject matter.

A formal, general characterization is hopeless in the case of selective parthood or componency.

the criterion for being clearly delimited and having a specific function within a car are arguably different from the criterion for being clearly delimited and having a specific function in a microphysical system, or in a living organism.

that selective parthood is specific to various fields, and depends on highly local features of things (such as cars), about which philosophy has nothing to say.

It is up to domain-specific theories of components to discriminate between them.

Philosophical mereology is about the formal features of parthood and some cognate relations and operations.