Editing Ontology (section)

== History ==
{{main|History of ontology}}

[[File:Kapila (cropped).png|thumb|upright=.8|alt=Depiction of Kapila|[[Kapila]] was one of the founding fathers of the dualist school of [[Samkhya]].<ref>{{harvnb|Ruzsa|loc=§ 1. History}}</ref>]]

The roots of ontology in [[ancient philosophy]] are speculations about the nature of being and the source of the universe. Discussions of the essence of reality are found in the [[Upanishads]], ancient Indian scriptures dating from as early as 700 BCE. They say that the universe has a divine foundation and discuss in what sense [[Brahman|ultimate reality]] is one or many.<ref>{{multiref | {{harvnb|Baird|2017|p=[https://books.google.com/books?id=Am1QDwAAQBAJ&pg=PA5 5]}} | {{harvnb|Grayling|2019|loc=§ Indian Philosophy}} }}</ref> [[Samkhya]], the first [[Āstika and nāstika|orthodox school of Indian philosophy]],{{efn|Its initial ideas were developed in the 7th and 6th centuries BCE but it was not until 350 CE that it received its classical and systematic formulation.<ref>{{multiref | {{harvnb|Ruzsa|loc=Lead Section}} | {{harvnb|Grayling|2019|loc=§ Indian Philosophy}} }}</ref>}} formulated an [[atheist]] dualist ontology based on the Upanishads, identifying [[Purusha|pure consciousness]] and [[Prakriti|matter]] as its two foundational principles.<ref>{{multiref | {{harvnb|Lopez|2010|p=[https://books.google.com/books?id=qejaEAAAQBAJ&pg=PA1426 1426]}} | {{harvnb|Ruzsa|loc=Lead Section}} | {{harvnb|Grayling|2019|loc=§ Indian Philosophy}} }}</ref> The later [[Vaisheshika]] school{{efn|The founding text of the school was written 500–300 BCE and the first major commentary on it is dated 400 CE.<ref>{{harvnb|Lopez|2010|p=[https://books.google.com/books?id=qejaEAAAQBAJ&pg=PA1426 1426]}}</ref>}} proposed a comprehensive system of categories.<ref>{{multiref | {{harvnb|Ambuel|1998|loc=§ 1. Categories}} | {{harvnb|Lopez|2010|p=[https://books.google.com/books?id=qejaEAAAQBAJ&pg=PA1426 1426]}} }}</ref> In [[ancient China]], [[Laozi]]'s (6th century BCE){{efn|The exact date is disputed and some theorists suggest a later date between the 4th and 3rd centuries BCE.<ref>{{multiref | {{harvnb|Dynes|2016|p=[https://books.google.com/books?id=pxjOEAAAQBAJ&pg=PA60 60]}} | {{harvnb|Littlejohn|loc=§ 2. Classical Sources for Our Understanding of Daoism}} }}</ref>}} [[Taoism]] examines the underlying order of the universe, known as [[Tao]], and how this order is shaped by the interaction of two basic forces, [[yin and yang]].<ref>{{multiref | {{harvnb|Littlejohn|loc=§ 5. Fundamental Concepts in the Daodejing}} | {{harvnb|Dynes|2016|pp=[https://books.google.com/books?id=pxjOEAAAQBAJ&pg=PA60 60–61]}} }}</ref> The philosophical movement of [[Xuanxue]] emerged in the 3rd century CE and explored the relation between being and non-being.<ref>{{multiref | {{harvnb|Chai|2020|p=[https://books.google.com/books?id=LSAAEAAAQBAJ&pg=PA19 19]}} | {{harvnb|Robinet|2013|loc=[https://books.google.com/books?id=R3Sp6TfzhpIC&pg=PA274 Chongxuan]}} }}</ref>

Starting in the 6th century BCE, [[Presocratic philosophy|Presocratic philosophers]] in [[ancient Greece]] aimed to provide rational explanations of the universe. They suggested that a first principle, such as water or fire, is the primal source of all things.<ref>{{multiref | {{harvnb|Graham|loc=§ 1. Presocratic Thought}} | {{harvnb|Rée|Urmson|2004|pp=[https://books.google.com/books?id=uewoLyIw_DQC&pg=PA308 308–309]}} }}</ref> [[Parmenides]] (c. 515–450 BCE) is sometimes considered the founder of ontology because of his explicit discussion of the concepts of being and non-being.<ref>{{multiref | {{harvnb|Kahn|2009|p=[https://books.google.com/books?id=DxE6zOaaGyIC&pg=PA143 143]}} | {{harvnb|Graham|loc=§ 6.a. Parmenides}} }}</ref> Inspired by Presocratic philosophy, [[Plato]] (427–347 BCE) developed his [[theory of forms]]. It distinguishes between unchangeable perfect forms and matter, which has a lower degree of existence and imitates the forms.<ref>{{multiref | {{harvnb|Hancock|2006|pp=184–185}} | {{harvnb|Hamlyn|2005|p=590}} | {{harvnb|Graham|loc=§ 3b. Metaphysics}} }}</ref> [[Aristotle]] (384–322 BCE) suggested an elaborate system of categories that introduced the concept of substance as the primary kind of being.<ref>{{multiref | {{harvnb|Thomasson|2022|loc=§ 1.1 Aristotelian Realism}} | {{harvnb|Studtmann|2024|loc=§ 2. The Ten-Fold Division}} | {{harvnb|Wardy|1998|loc=§ 1. Categories in Aristotle}} }}</ref> The school of [[Neoplatonism]] arose in the 3rd century CE and proposed an ineffable source of everything, called ''the One'', which is more basic than being itself.<ref>{{multiref | {{harvnb|Halfwassen|2014|p=[https://books.google.com/books?id=yhcWBAAAQBAJ&pg=PA185 185]}} | {{harvnb|Hancock|2006|pp=187–188}} | {{harvnb|Hamlyn|2005|pp=590–591}} | {{harvnb|Graham|loc=§ 5. Post-Hellenistic Thought}} }}</ref>

The [[problem of universals]] was an influential topic in medieval ontology. [[Boethius]] (477–524 CE) suggested that universals can exist not only in matter but also in the mind. This view inspired [[Peter Abelard]] (1079–1142 CE), who proposed that universals exist only in the mind.<ref>{{multiref | {{harvnb|Hancock|2006|pp=188–189}} | {{harvnb|Grayling|2019|loc=§ Boethius, § Abelard}} | {{harvnb|Marenbon|2009|p=[https://books.google.com/books?id=DYSVbvnDL8IC&pg=PA6 6]}} | {{harvnb|Sweeney|2016|pp=[https://books.google.com/books?id=orIYDAAAQBAJ&pg=PA10 10–11]}} }}</ref> [[Thomas Aquinas]] (1224–1274 CE) developed and refined fundamental ontological distinctions, such as the contrast between existence and [[essence]], between substance and accidents, and between [[matter and form]].<ref>{{multiref | {{harvnb|Buren|2023|p=[https://books.google.com/books?id=qnWzEAAAQBAJ&pg=PA53 53]}} | {{harvnb|Hancock|2006|p=189}} }}</ref> He also discussed the [[transcendentals]], which are the most general properties or modes of being.<ref>{{multiref | {{harvnb|Aertsen|2009|p=[https://books.google.com/books?id=lQ2xDwAAQBAJ&pg=PA117 117]}} | {{harvnb|Goris|Aertsen|2019|loc=§ 4.1 The first model: God as the cause of transcendental being (Thomas Aquinas)}} | {{harvnb|Kuhlmann|2010|p=1859}} }}</ref> [[John Duns Scotus]] (1266–1308) argued that all entities, including God, [[Univocity of being|exist in the same way]] and that each entity has a unique essence, called [[haecceity]].<ref>{{multiref | {{harvnb|Gilson|2018|loc=§ 1C Common Being, § 6C Unity of the Concrete}} | {{harvnb|Williams|2022|loc=§ 2.3 Divine Infinity and the Doctrine of Univocity, § 3.3 Universals and Individuation}} }}</ref> [[William of Ockham]] (c. 1287–1347 CE) proposed that one can decide between competing ontological theories by assessing which one uses the smallest number of elements, a principle known as [[Ockham's razor]].<ref>{{multiref | {{harvnb|Hancock|2006|p=190}} | {{harvnb|Grayling|2019|loc=§ Ockham}} | {{harvnb|Kuhlmann|2010|p=1859b}} }}</ref>

[[File:Zhu_xi.jpg|thumb|upright=.8|alt=Depiction of Zhu Xi|The [[Neo-Confucianism|Neo-Confucian]] philosopher [[Zhu Xi]] conceived the concept of [[Li (neo-Confucianism)|li]] as the organizing principle of the universe.<ref>{{harvnb|Thompson|2021|loc=§ 4. Natural Philosophy}}</ref>]]

In [[Islamic philosophy|Arabic-Persian philosophy]], [[Avicenna]] (980–1037 CE) combined ontology with [[theology]]. He identified God as a necessary being that is the source of everything else, which only has contingent existence.<ref>{{harvnb|Lizzini|2021|loc=§ 2.1 Ontology and Theology, § 2.4 Univocacy of Being and Ontological Distinction}}</ref> In 8th-century [[Indian philosophy]], the school of [[Advaita Vedanta]] emerged. It says that only a single all-encompassing entity exists, stating that the impression of a plurality of distinct entities is an [[Maya (religion)|illusion]].<ref>{{multiref | {{harvnb|Grayling|2019|loc=§ Indian Philosophy}} | {{harvnb|Perrett|2016|loc=§ The Medieval Period of Indian Philosophy}} | {{harvnb|Dalal|2021|loc=Lead Section, § 2.3 Two-Tiered Reality}} }}</ref> Starting in the 13th century CE, the [[Navya-Nyāya]] school built on Vaisheshika ontology with a particular focus on the problem of non-existence and negation.<ref>{{multiref | {{harvnb|Ambuel|1998|loc=§ 10. Nonexistence or absence}} | {{harvnb|Bhattacharya|2013|p=[https://books.google.com/books?id=mioW_kp5gzUC&pg=PA35 35]}} }}</ref> 9th-century China saw the emergence of [[Neo-Confucianism]], which developed the idea that a rational principle, known as ''[[Li (neo-Confucianism)|li]]'', is the ground of being and order of the cosmos.<ref>{{multiref | {{harvnb|Berthrong|loc=Lead Section, § 4. Traits, Themes and Motifs}} | {{harvnb|Wu|2022|p=[https://books.google.com/books?id=zRVmEAAAQBAJ&pg=PA56 56]}} | {{harvnb|Smart|2008|p=99}}}}</ref>

[[René Descartes]] (1596–1650) formulated a dualist ontology at the beginning of the modern period. It distinguishes between mind and matter as distinct substances that causally interact.<ref>{{multiref | {{harvnb|Hamlyn|2005|p=591}} | {{harvnb|Dehsen|2013|p=[https://books.google.com/books?id=cU7cAAAAQBAJ&pg=PA51 51]}} }}</ref> Rejecting Descartes's dualism, [[Baruch Spinoza]] (1632–1677) proposed a monist ontology according to which there is only a single entity that is identical to [[God or Nature|God and nature]].<ref>{{multiref | {{harvnb|Hancock|2006|p=190}} | {{harvnb|Hamlyn|2005|p=591}} }}</ref> [[Gottfried Wilhelm Leibniz]] (1646–1716), by contrast, said that the universe is made up of many simple substances, which are synchronized but do not interact with one another.<ref>{{multiref | {{harvnb|Hancock|2006|pp=190–191}} | {{harvnb|Hamlyn|2005|p=591}} | {{harvnb|Look|2020|loc=§ 4. Metaphysics: A Primer on Substance}} | {{harvnb|Menzel|2023|loc=1. Possible Worlds and Modal Logic}} }}</ref> [[John Locke]] (1632–1704) proposed his substratum theory, which says that each object has a featureless substratum that supports the object's properties.<ref>{{multiref | {{harvnb|Robinson|Weir|2024|loc=§ 2.5.1 Locke on 'pure substance in general'}} | {{harvnb|Kuhlmann|2010|p=1860b}} }}</ref>  [[Christian Wolff (philosopher)|Christian Wolff]] (1679–1754) was influential in establishing ontology as a distinct discipline, delimiting its scope from other forms of metaphysical inquiry.<ref>{{multiref | {{harvnb|Svare|2006|p=[https://books.google.com/books?id=60MsUE3K2ekC&pg=PA15 15]}} | {{harvnb|Hettche|Dyck|2019|loc=§ 5. Metaphysics}} }}</ref> [[George Berkeley]] (1685–1753) developed an idealist ontology according to which material objects are ideas perceived by minds.<ref>{{multiref | {{harvnb|Hancock|2006|p=192}} | {{harvnb|Hamlyn|2005|p=591}} }}</ref>

[[Immanuel Kant]] (1724–1804) rejected the idea that humans can have direct knowledge of independently existing things and their nature, limiting knowledge to the field of appearances. For Kant, ontology does not study external things but provides a system of [[Category (Kant)|pure concepts of understanding]].<ref>{{multiref | {{harvnb|Lorini|2015|pp=[https://books.google.com/books?id=rY1mCwAAQBAJ&pg=PA71 71, 75–76]}} | {{harvnb|Grier|2022|loc=§ 1. Preliminary Remarks: The Rejection of Ontology (general metaphysics) and the Transcendental Analytic}} }}</ref> Influenced by Kant's philosophy, [[Georg Wilhelm Friedrich Hegel]] (1770–1831) linked ontology and [[logic]]. He said that being and thought are identical and examined their foundational structures.<ref>{{multiref | {{harvnb|Redding|2020|loc=§ 3.1.2 Science of Logic}} | {{harvnb|Houlgate|2006|p=[https://books.google.com/books?id=Xz30HFjrIFAC&pg=PA117 117]}} }}</ref> [[Arthur Schopenhauer]] (1788–1860) rejected Hegel's philosophy and proposed that the world is an expression of a [[Voluntarism (philosophy)#Metaphysical voluntarism|blind and irrational will]].<ref>{{multiref | {{harvnb|Grayling|2019|loc=§ Schopenhauer}} | {{harvnb|Janaway|1999|pp=[https://academic.oup.com/book/2954/chapter-abstract/143638920?redirectedFrom=fulltext 248–249]}} }}</ref> [[Francis Herbert Bradley]] (1846–1924) saw absolute spirit as the ultimate and all-encompassing reality<ref>{{multiref | {{harvnb|Hancock|2006|p=193}} | {{harvnb|Hamlyn|2005|p=592}} | {{harvnb|Grayling|2019|loc=§ Idealism}} }}</ref> while denying that there are any external relations.<ref>{{harvnb|Johansson|2014|p=[https://books.google.com/books?id=Q31HBAAAQBAJ&pg=PA226 226]}}</ref> In Indian philosophy, [[Swami Vivekananda]] (1863–1902) expanded on Advaita Vedanta, emphasizing the unity of all existence.<ref>{{harvnb|Banhatti|1995|p=[https://books.google.com/books?id=jK5862eV7_EC&pg=PA151 151]}}</ref> [[Sri Aurobindo]] (1872–1950) sought to understand the world as an evolutionary manifestation of a divine consciousness.<ref>{{multiref | {{harvnb|Vernekar|1998|pp=81–86}} | {{harvnb|Lawrence|2018|p=415}} | {{harvnb|Phillips|1998|loc=Lead section, § Metaphysics}} }}</ref>

At the beginning of the 20th century, [[Edmund Husserl]] (1859–1938) developed [[Phenomenology (philosophy)|phenomenology]] and employed its method, the description of [[experience]], to address ontological problems.<ref>{{harvnb|Boedeker|2008|p=[https://books.google.com/books?id=mhiAcSw201kC&pg=PA156 156]}}</ref> This idea inspired his student [[Martin Heidegger]] (1889–1976) to clarify the meaning of being by exploring the mode of human existence.<ref>{{multiref | {{harvnb|Wheeler|2020|loc=§ 2.2.1 The Question}} | {{harvnb|Schalow|2019|p=[https://books.google.com/books?id=nJ27DwAAQBAJ&pg=PA139 139]}} }}</ref> [[Jean-Paul Sartre]] responded to Heidegger's philosophy by examining the relation between being and [[nothingness]] from the perspective of human existence, freedom, and consciousness.<ref>{{harvnb|Onof|loc=Lead Section}}</ref> Based on the phenomenological method, [[Nicolai Hartmann]] (1882–1950) developed a complex hierarchical ontology that divides reality into four levels: inanimate, biological, psychological, and spiritual.<ref>{{multiref | {{harvnb|Poli|2011|pp=[https://books.google.com/books?id=1Qya55bssVQC&pg=PA1 1, 11, 21–22]}} | {{harvnb|Peterson|Poli|2022|loc=§ 3. What is the Relationship between Thinking and Being?, § 5.2 Strata}} }}</ref>

[[File:Alexius Meinong 1900.jpg|thumb|upright=.8|alt=Photo of Alexius Meinong|[[Alexius Meinong]] proposed that there are [[nonexistent objects]].]]

[[Alexius Meinong]] (1853–1920) articulated a controversial ontological theory that includes nonexistent objects as part of being.<ref>{{harvnb|Aspenson|2016|loc=[https://books.google.com/books?id=pp4YDQAAQBAJ&pg=PA13 § 1.4 Essential Terms of Metaphysics: Ontology]}}</ref> Arguing against this theory, [[Bertrand Russell]] (1872–1970) formulated a fact ontology known as [[logical atomism]]. This idea was further refined by the early [[Ludwig Wittgenstein]] (1889–1951) and inspired [[D. M. Armstrong]]'s (1926–2014) ontology.<ref>{{multiref | {{harvnb|Proops|2022|loc=Lead Section}} | {{harvnb|Klement|2019|loc=Lead Section}} | {{harvnb|Mumford|2003|p=[https://books.google.com/books?id=kGGmBgAAQBAJ&pg=PA100 100]}} | {{harvnb|Loux|Crisp|2017|p=148}} }}</ref> [[Alfred North Whitehead]] (1861–1947), by contrast, developed a process ontology.<ref>{{multiref|{{harvnb|Desmet|Irvine|2022|loc=§ 6. Metaphysics}}|{{harvnb|Palmer|1998|p=[https://books.google.com/books?id=ZT2pI9IMiYUC&pg=PA175 175]}}}}</ref> [[Rudolf Carnap]] (1891–1970) questioned the objectivity of ontological theories by claiming that what exists depends on one's linguistic framework.<ref>{{multiref | {{harvnb|Chalmers|2009|p=78}} | {{harvnb|Hofweber|2023|loc=§ 4.4 Carnap’s rejection of ontology. (L1) meets (O4) and (the end of?) (O2)}} }}</ref> He had a strong influence on [[Willard Van Orman Quine]] (1908–2000), who analyzed the ontological commitments of scientific theories to solve ontological problems.<ref>{{multiref | {{harvnb|Ney|2014|pp=37–38, 40}} | {{harvnb|Van Inwagen|Sullivan|Bernstein|2023|loc=§ 4. The Methodology of Metaphysics}} }}</ref> Quine's student [[David Lewis (philosopher)|David Lewis]] (1941–2001) formulated the position of modal realism, which says that possible worlds are as real and concrete as the actual world.<ref>{{harvnb|Parent|loc=§ 2. Lewis' Realism}}</ref> Since the end of the 20th century, interest in applied ontology has risen in computer and information science with the development of conceptual frameworks for specific domains.<ref>{{multiref | {{harvnb|Guizzardi|2007|pp=[https://books.google.com/books?id=kR2iUt-CuwMC&pg=PA18 18–19]}} | {{harvnb|Sales|Guizzardi|2017|p=[https://books.google.com/books?id=F9s1DwAAQBAJ&pg=PA28 28]}} }}</ref>