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Perspective:Holistic
The holistic perspective deals with the concepts of whole and parts, following the commonly accepted definition of holism that looks at the whole as a world entity that is more (or "bigger") with respect to the simple sum of his parts.
Following this intuition, this perspective provides the ontological tools to define classes depending on the types of the parts of which an entity is composed, and to define classes depending on the type of the whole of which the entity is part. The former are called Whole-s and the latter Role-s.
Holistic perspective is based on a set of specialised mereological relations that put some constraints on the types of the subjects and the objects, and categorise the entities according to them.
An holistic part is a proper part of a different type with respect to the whole. More specifically, :x :hasHolisticPart :y if :x :hasProperPart :y and :y is not of the same type of :x.
For example, a molecule entity is an holistic part of a fluid (or a gas) entity since it is part of it and they belong to completely different types. The holism is manifested by the fact that a type (i.e. fluid, gas) can be defined as the mereological sum of entities of another specific type (i.e. molecule) with properties (i.e. viscosity, conductivity) that appear for the sum (i.e. the fluid) but are absent in the holistic parts (i.e. a molecule has no viscosity).
The implementation of holism in OWL 2 DL is limited by the language restrictions. In the EMMO the :hasHolisticPart relation is treated as the superclass of all holistic part relations that are specialised for specific types by declaring their domain and range.
For example the :hasParticipant relation is a sub-relation of :hasHolisticPart restricting the domain to processes and the range to objects.
A redundant part is a proper part of the same type with respect to the whole. More specifically, :x :hasRedundantPart :y if :x :hasProperPart :y and :y is of the same type of :x.
For example, a fluid entity can be parcelled in volume of fluids that retain the same type of the whole, up to the point in which the volumes are so small that they loose the characteristics of the continuum and should be treated as single molecules.
The Holistic class is the non-disjoint union of the Whole and Role classes. As for all the other perspectives, all Holistic individuals are Physical individuals, meaning that they are self-connected 4D entities whose temporal parts are all self-connected (convex 4D entities with respect to time).
An individual belonging to the Whole class stands for a world entity that the declarer considers as a whole according to whatever criteria he may consider. With the symbol 𝓗 we identify the most general criterion used to recognize an individual as belonging to the Whole class. The sub-classes of Whole categorize individuals according to some specializations of 𝓗. Sub-criteria 𝓐 and 𝓑 can be used to define A and B sub-classes of Whole (in general the ). It is unlikely that 𝓗 and its sub-criteria may be fully expressible in FOL or OWL-DL, so that 𝓗 will be expressed both by logical axioms and ontology annotations, making Whole and its sub-classes primitive entities for most of the cases.
The Part individuals are defined according to a specific EMMO mereological interpretation of holism: since the whole is more than the sum of its parts, then the requirement for an individual to be an holistic part of a whole is to not belong to the same class. This interpretation of an holistic part depends on the whole type, so that a world object is a part according to a whole class. An object can be at the same time a whole and an holistic part provided that two different whole criteria are used as a reference. The Part class collects all individuals that are parts of a whole regardless of the criteria.
Holistic is the a non-disjoint union of Whole and Part, while every one of their specialized sub-classes according to a class, like WholeForA and PartForA for Whole sub-classs A, are disjointed.
This work is licensed under a Creative Commons Attribution 4.0 International License.
