# One man's look at upper ontology

This article by Dan Polansky looks at some questions concerning upper ontology. The term upper ontology is used without deep understanding; if this is a misapplication, the article should better be renamed later.
Some of the questions:
* What is an entity?
* What is a person?
* What is an artifact?
* What is a living thing?
* What is an object?
The initial draft may address only some of the questions.

## Entity

One definition of entity could be this (M-W has other definitions):
* The root of ontology.
But that is a meta-definition. A similar meta-definition:
* A semantic node that has no hypernymic/superclass node.
Let us try something else:
* Anything (living or not) or anyone, including any referent of a word, phrase or a description, whether it exists or not, is real or imaginary/fictional, etc.
Corollary: Nile is an entity, and so is Bilbo. Numbers are entities. Geoforms are entities. Persons, animals and plants are entities. Time points and spatial points are entities and so are time regions and spatial regions.
Corollary: A mentally delineated part of an apple is an entity; since, it is referent of the description we just gave. One might object that this so-called entity only exists in the mind or by means by this description; a situation would be quite different if we used a knife to cut the apple into two halves. But an entity does not need to exist. Christian God is an entity and is omniponent, but (if you are an atheist), he does not exist.
Corollary: Words quasi-entity, pseudo-entity and non-entity should, properly taken, fail to refer. Since, there is no X such that X is not an entity.
We can formulate the manner in formal symbolic logic: For all X: entity(X). Alternatively, for all X, isInstance(X, entity); but then, it holds isInstance(entity, entity). We said that an entity may not exist. We get: Exists X, not exists(X); that seems like a contradiction, but it isn't since the first "exists" is a logical quantifier whereas the second one is a predicate, and then, these are two different meanings of "exist". It is this confusion that may lead some sources to indicate existence as a defining characteristic of entity, which I argue it isn't. Thus, Bilbo is an entity but does not exist. Moreover, someone can tell me about a person, name the person and describe the person. I build a representation of that person in the mind as an entity. Then I realize I was lied to and no such person exist. Then I may say, person so-and-so name does not exist. In terms of domain of discourse, the entity for that person has been established and it does not exist. (This would perhaps belong rather to an article on existence, but since existence is discussed as a potential defining characteristics of entity, it is not entirely off topic.)
The concept of entity is useful in definitions when one wants to avoid premature classification or what could perhaps be called ontological commitment. Thus, when "entity" is used as a genus in a definition, it is doubtful that it is genus proximus (nearby one). But then, some things defined need to be defined as entities and nothing more specific; these could perhaps be called high genera or something of the sort. Thus, e.g. animal could be a high genus, at least in some naive(?) ontology.
The word thing could be used as a synonym for entity except that it is often or usually used in a more specific way; e.g. human persons would not be things.

## Person

A quick sketch of a definition:
* An entity that can be a referent of who or someone (personal pronouns).
Another sketch:
* An entity with a non-trivial representative and executive agency.
For more, see An analysis of the concept of person.

## Artifact

A first attempt of a definition:
* Anything made by humans.
Some complications:
* What if the thing is made by robots (and these are made by humans)? That would also be an artifact.
* What if the entity is a result of animal husbandry, such as a domestic cow or a dog? These entities are somewhat artificial, but they would not probably come under the head of artifact.
* What if the thing is made by an animal, such as a beaver dam? If beaver dam an artifact? Wikipedia uses the label "structures built by animals".
We may complicate the matter by considering various degrees of artificiality and various degrees of being an artifact. Early flintstones could have featured minimum amount/scope of modification, and then, their being an artifact would have been borderline. One can even as if turn a found a flintstone into an artifact without a modification, by the act of careful selection via an extensive search; this matches a very deformed concept of an artifact, but maybe someone would find this convincing. This idea is perhaps inspired by Duchamp's alleged turning something into art merely by the act of choice, requiring no modification of the object (W:Fountain (Duchamp)).
We may consider a plastic chair to be more artificial than a wooden chair since the material of the latter is more natural. They seem to have the same degree of being an artifact (artifacthood), but not the same degree of artificiality. But then, perhaps the concept of artificiality vs. naturality (if it is a single concept) points to directions other than having to do with artifacts, e.g. natural vs. artificial human behavior.

## Living thing

A first attempt of a definition:
* Anything that grows, reproduces and has a metabolism.
A subclass-based alternative:
* Any animal, plant, fungus, microorganism or virus.
Here, viruses are something of a special case/borderline case.
The subclass-based definition abandons genus-differentia and gains clarity as for scope.

## Other

The following are yet to be covered:
* Object
* Process
* Event
* Action
* Activity
* Relation
* Agent
* Negative object? Hole?
* Quality
* State