Editing Existence (section)

=== First-order theories ===
According to first-order theories, existence is a property of individuals. These theories are less-widely accepted than second-order theories but also have some influential proponents. There are two types of first-order theories: Meinongianism and universalism.<ref>{{multiref |1={{harvnb|Casati|Fujikawa|loc=Lead Section, §2. Existence as a First-Order Property and Its Relation to Quantification}} |2={{harvnb|Nelson|2022|loc=Lead Section}} }}</ref>

==== Meinongianism ====
Meinongianism, which describes existence as a property of some but not all entities, was first formulated by [[Alexius Meinong]]. Its main assertion is that there are some entities that do not exist, meaning [[objecthood]] is independent of existence. Proposed examples of nonexistent objects are merely possible objects such as flying pigs, as well as fictional and mythical objects like Sherlock Holmes and Zeus. According to this view, these objects are real and have being, even though they do not exist.<ref>{{multiref |1={{harvnb|Casati|Fujikawa|loc=§2a. Meinongianism}} |2={{harvnb|Lowe|2005|loc=[https://www.oxfordreference.com/display/10.1093/acref/9780199264797.001.0001/acref-9780199264797-e-828 Existence]}} }}</ref> Meinong states there is an object for any combination of properties. For example, there is an object that only has the single property of "being a singer" with no other properties. This means neither the attribute of "wearing a dress" nor the absence of it applies to this object. Meinong also includes impossible objects like round squares in this classification.<ref>{{multiref |1={{harvnb|Nelson|2022|loc=§ 2. Meinongianism}} |2={{harvnb|Casati|Fujikawa|loc=§2a. Meinongianism}} }}</ref>

[[File:Alexius Meinong 1900.jpg|alt=Photo of Alexius Meinong|left|thumb|upright|According to [[Alexius Meinong]], there are some entities that do not exist.]]

According to Meinongians, sentences describing Sherlock Holmes and Zeus refer to nonexisting objects. They are true or false depending on whether these objects have the properties ascribed to them.<ref>{{multiref |1={{harvnb|Casati|Fujikawa|loc=§2a. Meinongianism}} |2={{harvnb|Lowe|2005|loc=[https://www.oxfordreference.com/display/10.1093/acref/9780199264797.001.0001/acref-9780199264797-e-828 Existence]}} |3={{harvnb|Küng|2012|p=[https://books.google.com/books?id=mprnCAAAQBAJ&pg=PA208 208]}} }}</ref> For instance, the sentence "Pegasus has wings" is true because having wings is a property of Pegasus, even though Pegasus lacks the property of existing.<ref name="auto1">{{harvnb|Mackie|1998|loc=§1 Objects and Existence}}</ref>

One key motivation of Meinongianism is to explain how negative singular existentials like "Ronald McDonald does not exist" can be true. Meinongians accept the idea that singular terms like "Ronald McDonald" refer to individuals. For them, a negative singular existential is true if the individual it refers to does not exist.<ref>{{multiref |1={{harvnb|Nelson|2022|loc=§ 2. Meinongianism}} |2={{harvnb|Mackie|1998|loc=§1 Objects and Existence}} }}</ref>

Meinongianism has important implications for understandings of quantification. According to an influential view defended by [[Willard Van Orman Quine]], the domain of quantification is restricted to existing objects. This view implies quantifiers carry [[ontological commitments]] about what exists and what does not exist. Meinongianism differs from this view by saying the widest domain of quantification includes both existing and nonexisting objects.<ref name="auto3"/>

Some aspects of Meinongianism are controversial and have received substantial criticism. According to one objection, one cannot distinguish between being an object and being an existing object.<ref name="auto1"/> A closely related criticism states objects cannot have properties if they do not exist.<ref name="auto1"/> A further objection is that Meinongianism leads to an "overpopulated universe" because there is an object corresponding to any combination of properties.<ref name="auto3"/> A more specific criticism rejects the idea that there are incomplete and impossible objects.<ref>{{multiref |1={{harvnb|Nelson|2022|loc=§ 2. Meinongianism}} |2={{harvnb|Casati|Fujikawa|loc=§2a. Meinongianism}} |3={{harvnb|Casati|Fujikawa|loc=§2a. Meinongianism}} |4={{harvnb|Jacquette|2015|pp=[https://books.google.com/books?id=7jswCgAAQBAJ&pg=PA78 78–79, 180]}} }}</ref>

==== Universalism ====
Universalists agree with Meinongians that existence is a property of individuals but deny there are nonexistent entities. Instead, universalists state existence is a universal property; all entities have it, meaning everything exists. One approach is to say existence is the same as self-identity. According to the [[law of identity]], every object is identical to itself or has the property of self-identity. This can be expressed in [[predicate logic]] as <math>\forall x (x=x)</math>.<ref name="auto5">{{harvnb|Casati|Fujikawa|loc=§2b. Universalism}}</ref>

An influential argument in favor of universalism is that the denial of the existence of something is contradictory. This conclusion follows from the premises that one can only deny the existence of something by referring to that entity and that one can only refer to entities that exist.<ref name="auto5"/>

Universalists have proposed different ways of interpreting negative singular existentials. According to one view, names of fictional entities like "Ronald McDonald" refer to [[abstract object]]s, which exist even though they do not exist in space and time. This means, when understood in a strict sense, all negative singular existentials are false, including the assertion that "Ronald McDonald does not exist". Universalists can interpret such sentences slightly differently in relation to the context. In everyday life, for example, people use sentences like "Ronald McDonald does not exist" to express the idea that Ronald McDonald does not exist as a concrete object, which is true.<ref>{{multiref |1={{harvnb|Nelson|2022|loc=§ 3. An Anti-Meinongian First-Order View}} |2={{harvnb|Casati|Fujikawa|loc=§2b. Universalism}} }}</ref> Another approach is to understand negative singular existentials as neither true nor false but [[Meaning (philosophy)|meaningless]] because their singular terms do not refer to anything.<ref>{{harvnb|Nelson|2022|loc=§ 3. An Anti-Meinongian First-Order View}}</ref>