I'm not sure if I agree. Is it the case that We cannot consider that both, caterpillar and butterfly, are two phases of the same thing (a Lepidopteran)?
MW: Indeed caterpillar and butterfly are two phases (I would say states) of a Lepidoperan. That is what makes it a phased sortal (I think it is actually the Lepidopteran that is the sortal, with caterpillar and butterfly as the phases).
Considering the next terms: Baby, Toddler, Child,Teenager,Young Adult,Adult and Elder. Seems that they represent accidental properties of Person. Do you agree?
MW: No. These too are phases, and they are necessary (provided you survive) not accidental. A door being open or closed is an accidental property.
There are many works in the literature that consider these terms, representations of phased sortals.
But in these examples, the transitions between phases seem to be unidiretional. (I confess that I don't know if it is an necessary constraint in phased sortals).
MW: I think not. Another example Guarino and Welty give is the change between region and country (which is possibly reversible). However, I am not convinced about the utility of phased sortals. (I generally do not buy in to the ontological commitments that are implicit in Ontoclean, though I think the principle of looking at the meta-properties of relations is a good one.)
In the case of the partition induced by the classes "Person that likes icecream" and "Person that do not likes icecream", seems to accept bidiretional transitions between phases.
MW: In that case, what would not be a phased sortal? For any property X you can construct a not X. This is not the nature of a sortal. Sortals are the basic categories that things are divided into, and the distinction between these and accidental properties is one of the major ones amongst classes.
Tel: +44 1489 880185
Mobile: +44 750 3385279
This email originates from Information Junction Ltd. Registered in England and Wales No. 6632177.
Registered office: 2 Brookside, Meadow Way, Letchworth Garden City, Hertfordshire, SG6 3JE.