Ontology

=== States of affairs and events ===
[[State of affairs (philosophy)|States of affairs]] are complex entities, in contrast to substances and properties, which are usually conceived as simple.<ref name="Borchert2"/><ref>{{cite book |last=Meinertsen |first=Bo R. |title=Metaphysics of States of Affairs: Truthmaking, Universals, and a Farewell to Bradley's Regress |year=2018 |publisher=Springer Singapore |page=1 |url=https://philpapers.org/rec/MEIMOS-2}}</ref> Complex entities are built up from or constituted by other entities. Atomic states of affairs are constituted by one particular and one property exemplified by this particular.<ref name="Sandkühler2"/><ref name="Textor">{{cite web |last=Textor |first=Mark |title=States of Affairs |url=https://plato.stanford.edu/entries/states-of-affairs/ |website=The Stanford Encyclopedia of Philosophy |publisher=Metaphysics Research Lab, Stanford University |access-date=9 January 2021 |date=2020}}</ref> For example, the state of affairs that Socrates is wise is constituted by the particular "Socrates" and the property "wise". Relational states of affairs involve several particulars and a relation connecting them. States of affairs that ''obtain'' are also referred to as [[Fact#In philosophy|facts]].<ref name="Textor"/> It is controversial which ontological status should be ascribed to states of affairs that do not obtain.<ref name="Sandkühler2"/> States of affairs have been prominent in 20th-century ontology as various theories were proposed to describe the world as composed of states of affairs.<ref name="Borchert2"/><ref>{{cite book |last1=Wittgenstein |first1=Ludwig |last2=Colombo |first2=G. C. M. |last3=Russell |first3=Bertrand |title=Tractatus Logico-Philosophicus |date=1922 |publisher=[[Fratelli Bocca]] |url=https://philpapers.org/rec/WITTL-14}}</ref><ref>{{cite book |last=Armstrong |first=D. M. |title=A World of States of Affairs |date=1996 |publisher=Cambridge University Press |url=https://philpapers.org/rec/ARMAWO-3}}</ref> It is often held that states of affairs play the role of [[truthmaker]]s: judgments or assertions are true because the corresponding state of affairs obtains.<ref name="Textor"/><ref>{{cite web |last=Asay |first=Jamin |title=Truthmaker Theory |url=https://iep.utm.edu/truth-ma/ |website=Internet Encyclopedia of Philosophy |access-date=9 January 2021}}</ref>

[[Event (philosophy)|Events]] take place in time, they are sometimes thought of as involving a change in the form of acquiring or losing a property, like the lawn's becoming dry.<ref name="Honderich2"/> But on a liberal view, the retaining of a property without any change may also count as an event, e.g., the lawn's staying wet.<ref name="Honderich2">{{cite book |last=Honderich |first=Ted |title=The Oxford Companion to Philosophy |date=2005 |publisher=Oxford University Press |url=https://philpapers.org/rec/HONTOC-2 |chapter=events}}</ref><ref name="Kim2"/> Some philosophers see events as universals that can repeat at different times, but the more dominant view is that events are particulars and therefore non-repeatable.<ref name="Kim2">{{cite book |last1=Kim |first1=Jaegwon |last2=Sosa |first2=Ernest |last3=Rosenkrantz |first3=Gary S. |title=A Companion to Metaphysics |publisher=Wiley-Blackwell |url=https://philpapers.org/rec/KIMACT-9 |chapter=event theory|year=1994 }}</ref> Some events are complex in that they are composed of a sequence of events, often referred to as a process.<ref>{{cite book |last=Craig |first=Edward |title=Routledge Encyclopedia of Philosophy |date=1996 |publisher=Routledge |url=https://philpapers.org/rec/BEAREO |chapter=processes}}</ref> But even simple events can be conceived as complex entities involving an object, a time and the property exemplified by the object at this time.<ref>{{cite book |last=Audi |first=Robert |title=The Cambridge Dictionary of Philosophy |publisher=Cambridge University Press |url=https://philpapers.org/rec/AUDTCD-2 |chapter=event|year=1999 }}</ref><ref>{{cite web |last=Schneider |first=Susan |title=Events |url=https://iep.utm.edu/events/ |website=Internet Encyclopedia of Philosophy}}</ref> So-called [[process philosophy]] or [[process ontology]] ascribes ontological primacy to changes and processes as opposed to the emphasis on static being in the traditionally dominant substance metaphysics.<ref>{{cite web |last=Seibt |first=Johanna |title=Process Philosophy |url=https://plato.stanford.edu/entries/process-philosophy/ |website=The Stanford Encyclopedia of Philosophy |publisher=Metaphysics Research Lab, Stanford University |access-date=9 January 2021 |date=2020}}</ref><ref>{{cite web |last=Hustwit |first=J. R. |title=Process Philosophy |url=https://iep.utm.edu/processp/ |website=Internet Encyclopedia of Philosophy |access-date=9 January 2021}}</ref>