Editing Existence (section)

=== Western philosophy ===
[[Western philosophy]] originated with the [[Presocratic philosophy|Presocratic philosophers]], who aimed to replace earlier [[Greek mythology|mythological accounts]] of the universe by providing rational explanations based on foundational principles of all existence. Some, like [[Thales]] (c. 624–545 BCE) and [[Heraclitus]] (c. 540–480 BCE), suggested concrete principles like water and fire are the root of existence. [[Anaximander]] (c. 610–545 BCE) opposed this position; he believed the source must lie in an abstract principle that is beyond the world of human perception.<ref>{{multiref |1={{harvnb|Graham|loc=Lead Section, §  1. Presocratic Thought}} |2={{harvnb|Duignan|2010|pp=[https://books.google.com/books?id=MfBS-RXJ5RsC&pg=PA9 9–11]}} }}</ref>

[[File:"The School of Athens" by Raffaello Sanzio da Urbino (cropped).jpg|left|thumb|alt=Painting of Plato and Aristotle|upright|[[Plato]] and his student [[Aristotle]] disagreed on whether form and matter depend on one another for their existence.]]

[[Plato]] (428/427–348/347 BCE) argued that different types of entities have different degrees of existence and that shadows and images exist in a weaker sense than regular material objects. He said unchangeable [[Platonic forms]] have the highest type of existence, and saw material objects as imperfect and impermanent copies of Platonic forms.<ref>{{multiref |1={{harvnb|Van Inwagen|2023}} |2={{harvnb|Daly|2009|pp=[https://books.google.com/books?id=Bt99AgAAQBAJ&pg=PA227 227–228]}} }}</ref>

Philosopher [[Aristotle]] (384–322 BCE) accepted Plato's idea that forms are different from matter, but he challenged the idea that forms have a higher type of existence. Instead, he believed forms cannot exist without matter.<ref>{{multiref |1={{harvnb|Trott|2019|pp=[https://books.google.com/books?id=SHsxEAAAQBAJ&pg=PA109 109–110]}} |2={{harvnb|Grayling|2019|loc=§ Aristotle}} }}</ref> He stated: "being is said in many ways" and explored how different types of entities have different modes of existence. For example, he distinguished between [[Ousia|substances]] and their [[Accident (philosophy)|accidents]], and between [[potentiality and actuality]].<ref>{{multiref | {{harvnb|Daly|2009|pp=[https://books.google.com/books?id=Bt99AgAAQBAJ&pg=PA228 228–229]}} | {{harvnb|Menn|2021|loc=§1. The Senses of Being and the Necessity of Δ. 7}} | {{harvnb|Kung|1986|pp=[https://www.jstor.org/stable/27743750 3–4]}} }}</ref>{{efn|Unlike abstract possibility, potentiality is real power possessed by a thing to undergo certain changes. For example, an [[acorn]] has the potential to become a fully grown [[oak]] but not an [[elm]].<ref>{{multiref | {{harvnb|Cohen|Reeve|2021|loc=§ 12. Actuality and Potentiality}} | {{harvnb|Ackrill|2005|p=[https://books.google.com/books?id=Nq7lGO4Fn4kC&pg=PA34 34]}} }}</ref>}}

[[Neoplatonists]] like [[Plotinus]] (204–270 CE) suggested reality has a hierarchical structure. They believed a transcendent entity, called "the One" or "the Good", is responsible for all existence. From it emerges the intellect, which in turn gives rise to the soul and the material world.<ref>{{multiref | {{harvnb|Graham|loc=§ 6. Post-Hellenistic Thought}} | {{harvnb|Adamson|2015|pp=209–215}} | {{harvnb|Emilsson|2005|pp=357–388}} | {{harvnb|Lawson|2004|p=[https://books.google.com/books?id=1AY1ALzh9V0C&pg=PA200 200]}} }}</ref>

[[File:Anselm of Canterbury2.png|thumb|alt=Painting of Anselm of Canterbury|upright=.7|[[Anselm of Canterbury]] is known for his formulation of the ontological argument aiming to prove the existence of God.]]

In [[medieval philosophy]], [[Anselm of Canterbury]] (1033–1109 CE) formulated the influential [[ontological argument]], which aims to deduce the existence of God from the concept of God. Anselm defined God as the greatest conceivable being. He reasoned that an entity that did not exist outside his mind would not be the greatest conceivable being, leading him to the conclusion God exists.<ref>{{multiref |1={{harvnb|Grayling|2019|loc=§ Anselm}} |2={{harvnb|Dehsen|2013|p=[https://books.google.com/books?id=cU7cAAAAQBAJ&pg=PA10 10]}} |3={{harvnb|Prior|2006|pp=493–494}} }}</ref>

[[Thomas Aquinas]] (1224–1274 CE) distinguished between the essence of a thing and its existence. According to him, the essence of a thing constitutes its fundamental nature. He argued it is possible to understand what an object is and grasp its essence, even if one does not know whether the object exists. He concluded from this observation that existence is not part of the qualities of an object and should be understood as a separate property.<ref name="auto2"/> Aquinas also considered the problem of [[creation from nothing]] and said only God has the power to truly bring new entities into existence. These ideas later inspired metaphysician [[Gottfried Wilhelm Leibniz]]'s (1646–1716) theory of creation; Leibniz said to create is to confer actual existence to possible objects.<ref>{{harvnb|Prior|2006|p=494}}</ref>

The philosophers [[David Hume]] (1711–1776) and [[Immanuel Kant]] (1724–1804) rejected the idea that existence is a property. According to Hume, objects are [[Bundle theory|bundles of qualities]]. He said existence is not a property because there is no impression of existence besides the bundled qualities.<ref>{{multiref |1={{harvnb|Nelson|2022|loc=Lead Section}} |2={{harvnb|Prior|2006|p=495}} }}</ref> Kant came to a similar conclusion in his criticism of the ontological argument; according to him, this proof fails because one cannot deduce from the definition of a concept whether entities described by this concept exist. Kant said existence does not add anything to the concept of the object; it only indicates this concept is exemplified.<ref>{{multiref |1={{harvnb|Nelson|2022|loc=Lead Section}} |2={{harvnb|Casati|Fujikawa|loc=§1. Existence as a Second-Order Property and Its Relation to Quantification}} }}</ref> According to philosopher [[Georg Wilhelm Friedrich Hegel]] (1770–1831), there is no pure being or pure nothing, only becoming.<ref>{{multiref | {{harvnb|Rosen|2014|pp=15, 113–114}} | {{harvnb|Magee|2010|pp=47–48}} }}</ref>

[[File:Franz Brentano in Vienna, 1875.png|thumb|left|alt=Photo of Franz Brentano|upright=.7|[[Franz Brentano]] defended the idea that all judgments are existential judgments.]]

Philosopher and psychologist [[Franz Brentano]] (1838–1917) agreed with Kant's criticism and his position that existence is not a real predicate. Brentano used this idea to develop his theory of judgments, which states all judgments are existential judgments; they either affirm or deny the existence of something. He stated judgments like "some zebras are striped" have the logical form "there is a striped zebra" while judgments like "all zebras are striped" have the logical form "there is not a non-striped zebra".<ref>{{multiref |1={{harvnb|Kriegel|2018|pp=[https://books.google.com/books?id=Yz5MDwAAQBAJ&pg=PA103 103–104, 119]}} |2={{harvnb|Brandl|Textor|2022|loc=Lead Section, §1.3 Part III: Existential Judgements, §2. Brentano and His Precursors on Existential Judgement}} |3={{harvnb|Rollinger|2013|p=[https://books.google.com/books?id=6FJFBgAAQBAJ&pg=PA226 226]}} |4={{harvnb|Husserl|2019|p=[https://books.google.com/books?id=ikqzDwAAQBAJ&pg=PA184 184]}} }}</ref>

[[Gottlob Frege]] (1848–1925) and [[Bertrand Russell]] (1872–1970) aimed to refine the idea of what it means that existence is not a regular property. They distinguished between regular first-order properties of individuals and second-order properties of other properties. According to their view, existence is the second-order property of "being instantiated".<ref>{{multiref |1={{harvnb|Nelson|2022|loc=Lead Section}} |2={{harvnb|Blackburn|2008|loc=[https://www.oxfordreference.com/display/10.1093/oi/authority.20110803095804522 Existence]}} }}</ref> Russell further developed the idea that general sentences like "lions exist" are at their most fundamental form about individuals by stating that there is an individual that is a lion.<ref>{{harvnb|Prior|2006|pp=496–498}}</ref>

Willard Van Orman Quine (1908–2000) followed Frege and Russell in accepting existence as a second-order property. He drew a close link between existence and the role of quantification in formal logic.<ref>{{multiref |1={{harvnb|Lowe|2005|loc=[https://www.oxfordreference.com/display/10.1093/acref/9780199264797.001.0001/acref-9780199264797-e-828 Existence]}} |2={{harvnb|Casati|Fujikawa|loc=§2a. Meinongianism}} }}</ref> He applied this idea to scientific theories and stated a scientific theory is committed to the existence of an entity if the theory quantifies over this entity. For example, if a theory in biology asserts that "there are populations with genetic diversity", this theory has an ontological commitment to the existence of populations with genetic diversity.<ref>{{harvnb|Casati|Fujikawa|loc=§1. Existence as a Second-Order Property and Its Relation to Quantification, §2a. Meinongianism}}</ref> Alexius Meinong (1853–1920) was an influential critic of second-order theories and developed the alternative view that existence is a property of individuals and that not all individuals have this property.<ref>{{multiref |1={{harvnb|Nelson|2022|loc=Lead Section}} |2={{harvnb|Casati|Fujikawa|loc=§2a. Meinongianism}} }}</ref>

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