Editing Abstract and concrete (section)

{{Short description|Metaphysics concept covering the divide between two types of entities}}
{{Redirect|Abstract entity|conceptual abstraction|Abstraction|the album by Kiana|Kiana (band)#Discography{{!}}Abstract Entity}}

In [[philosophy]] and [[the arts]], a fundamental distinction exists between '''abstract''' and '''concrete''' entities. While there is no [[Consensus decision-making|universally accepted]] definition, common examples illustrate the difference: [[number]]s, [[set (mathematics)|sets]], and [[idea]]s are typically classified as abstract objects, whereas [[plant]]s, [[dogs]], and [[planet]]s are considered concrete objects.<ref name="Rosen">{{cite web |last1=Rosen |first1=Gideon |title=Abstract Objects |url=https://plato.stanford.edu/entries/abstract-objects/ |website=The Stanford Encyclopedia of Philosophy |publisher=Metaphysics Research Lab, Stanford University |access-date=4 January 2021 |date=2020}}</ref>

Philosophers have proposed several criteria to define this distinction:

# ''Spatiotemporal existence'' – Abstract objects exist outside [[space-time]], while concrete objects exist within space-time.
# ''Causal influence'' – Concrete objects can cause and be affected by other entities (e.g., a rock breaking a window), whereas abstract objects (e.g., the number 2) lack causal powers and do not cause anything to happen in the physical world.
# ''Metaphysical relation'' – In [[metaphysics]], concrete objects are specific, individual things ([[Particular|particulars]]), while abstract objects represent general concepts or categories ([[Universal (metaphysics)|universals]]).
# ''Ontological domain'' – Concrete objects belong to the physical realm (or both the physical and mental realms), whereas abstract objects belong to neither.<ref>{{cite book |last1=Honderich |first1=Ted |title=The Oxford Companion to Philosophy |date=2005 |publisher=Oxford University Press |url=https://philpapers.org/rec/HONTOC-2 |chapter=abstract entities}}</ref><ref>{{cite book |last1=Craig |first1=Edward |title=Routledge Encyclopedia of Philosophy |date=1996 |publisher=Routledge |url=https://philpapers.org/rec/BEAREO |chapter=Abstract objects}}</ref><ref name="A Glossary of Literary Terms">{{cite book|title=A Glossary of Literary Terms|url=https://books.google.com/books?id=SUEtEa9nUWQC&pg=PA60|access-date=18 September 2012|isbn=978-0495898023|last1=Abrams|first1=Meyer Howard|last2=Harpham|first2=Geoffrey Galt|year=2011| publisher=Cengage Learning }}</ref> 

Another view is that it is the distinction between contingent existence versus necessary existence; however, philosophers differ on which type of existence here defines abstractness, as opposed to concreteness. Despite this diversity of views, there is broad agreement concerning most objects as to whether they are abstract or concrete,<ref name="Rosen"/> such that most interpretations agree, for example, that rocks are concrete objects while numbers are abstract objects.

Abstract objects are most commonly used in [[philosophy]], particularly metaphysics, and [[semantics]]. They are sometimes called '''''abstracta''''' in contrast to '''''concreta'''''. The term ''abstract object'' is said to have been coined by [[Willard Van Orman Quine]].<ref>{{cite book|last=Armstrong|first=D. M.|title=Sketch for a systematic metaphysics|year=2010|publisher=Oxford University Press|location=Oxford|isbn=9780199655915|page=2}}</ref> [[Abstract object theory]] is a discipline that studies the nature and role of abstract objects. It holds that properties can be related to objects in two ways: through exemplification and through encoding. Concrete objects exemplify their properties while abstract objects merely encode them. This approach is also known as the [[dual copula strategy]].{{sfn|Zalta|1983|p=33}}