Ontological argument Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.Anti-spam check. Do not fill this in! ====Alvin Plantinga==== [[File:AlvinPlantinga.JPG|thumb|upright=0.7|Alvin Plantinga criticized Malcolm's and Hartshorne's ontological arguments and proposed a variation of his own.]] Christian [[Analytic philosophy|Analytic philosopher]] [[Alvin Plantinga]]<ref> {{cite news |date=April 11, 2010 |title=Evolution, Shibboleths, and Philosophers |publisher=[[The Chronicle of Higher Education]] |url=http://chronicle.com/article/Evolution-Shibboleths-and/64990/ |access-date=2010-04-28 |quote=Like any Christian (and indeed any theist), I believe that the world has been created by God, and hence 'intelligently designed'.}}</ref> criticized Malcolm's and Hartshorne's arguments, and offered an alternative. Plantinga developed his argument in the books titled ''The nature of necessity'' (1974; ch. 10) and ''God, Freedom and Evil'' (1975; part 2 c).<ref name="Leslie,2017">{{cite book|url= http://www.RationalRealm.com/philosophy/metaphysics/plantinga-ontological-argument.html |title=Plantinga's Ontological Argument|last1=Leslie|first1=Alan|format=PDF|pages=3–4|year=2017|archive-url=https://web.archive.org/web/20170506071340/http://www.RationalRealm.com/philosophy/metaphysics/plantinga-ontological-argument.html|archive-date=May 6, 2017|url-status=live}}</ref> He argued that, if Malcolm does prove the necessary existence of the greatest possible being, it follows that there is a being which exists in all worlds whose greatness in ''some'' worlds is not surpassed. It does not, he argued, demonstrate that such a being has unsurpassed greatness in this actual world.<ref name="Plantinga, Sennett 1998">{{harvnb|Plantinga|1998|pp=65–71}}.</ref> In an attempt to resolve this problem, Plantinga differentiated between "greatness" and "excellence". A being's excellence in a particular world depends only on its properties in that world; a being's greatness depends on its properties in all worlds. Therefore, the greatest possible being must have maximal excellence in every possible world. Plantinga then restated Malcolm's argument, using the concept of "maximal greatness". He argued that it is possible for a being with maximal greatness to exist, so a being with maximal greatness exists in a possible world. If this is the case, then a being with maximal greatness exists in every world, and therefore in this world.<ref name="Plantinga, Sennett 1998" /> The conclusion relies on a form of [[axiom S5|modal axiom 5 of S5]], which states that if something is possibly true, then its possibility is necessary (it is possibly true in all worlds; in symbols: <math>\Diamond A\to \Box\Diamond A</math>). Plantinga's version of S5 suggests that "To say that p is possibly necessarily true is to say that, with regard to one possible world, it is true at all worlds; but in that case it is true at all worlds, and so it is simply necessary."<ref>{{Cite book|url=https://books.google.com/books?id=veGCAgAAQBAJ&dq=%22possibly+necessarily+true%22+then+it+is+necessarily+true+plantinga&pg=PA128|title=Medieval Philosophy: An Historical and Philosophical Introduction|first=John|last=Marenbon|date=October 2, 2006|publisher=Routledge|isbn=9781134461837|via=Google Books}}</ref> In other words, to say that p is necessarily possible means that p is true in at least one possible world W (if it is an actual world; Plantinga also used Axioms B of S5: <math>A\to\Box\Diamond A</math>) and thus it is true in all worlds because its omnipotence, omniscience, and moral perfection are its essence. In the 1975 version of the argument, Plantinga clarified that<ref name="Leslie,2017" /> "it follows that if W had been actual, it would have been impossible that there be no such being. That is, if W had been actual, :(33) ''There is no omnipotent, omniscient, and morally perfect being'', would have been an impossible proposition. But if a proposition is impossible in at least one possible world, then it is impossible in every possible world; what is impossible does not vary from world to world. Accordingly (33) is impossible in the actual world, i.e., impossible ''simpliciter''. But if it is impossible that there be no such being, then there actually exists a being that is omnipotent, omniscient, and morally perfect; this being, furthermore, has these qualities ''[[Essence|essentially]]'' and exists in every possible world." A version of his argument may be formulated as follows:<ref name="oppy" /> # A being has ''maximal excellence'' in a given possible world ''W'' if and only if it is [[omnipotence|omnipotent]], [[omniscience|omniscient]] and wholly good in ''W''; and # A being has ''maximal greatness'' if it has maximal excellence in every possible world. # It is possible that there is a being that has maximal greatness. (Premise) # Therefore, possibly, it is necessarily true that an omniscient, omnipotent, and perfectly good being exists. # Therefore, (by axiom 5 of S5) it is necessarily true that an omniscient, omnipotent and perfectly good being exists. # Therefore, an omniscient, omnipotent and perfectly good being exists. Plantinga argued that, although the first premise is not rationally established, it is not contrary to reason. [[Michael Martin (philosopher)|Michael Martin]] argued that, if certain components of perfection are contradictory, such as omnipotence and omniscience, then the first premise is contrary to reason. Martin also proposed parodies of the argument, suggesting that the existence of anything can be demonstrated with Plantinga's argument, provided it is defined as perfect or special in every possible world.<ref>{{cite book | title=Philosophy of religion: an anthology | publisher=Wiley-Blackwell | author=Martin, Michael | year=2003 | pages=282–293 | isbn=978-0-631-21471-7}}</ref> Another Christian philosopher, [[William Lane Craig]], characterizes Plantinga's argument in a slightly different way: # It is possible that a maximally great being exists. # If it is possible that a maximally great being exists, then a maximally great being exists in some possible world. # If a maximally great being exists in some possible world, then it exists in every possible world. # If a maximally great being exists in every possible world, then it exists in the actual world. # If a maximally great being exists in the actual world, then a maximally great being exists. # Therefore, a maximally great being exists.<ref>{{cite book |author=Craig |first=William Lane |title=Reasonable faith |publisher=Crossway |year=2008 |isbn=978-1-4335-0115-9 |pages=184–185}}</ref> According to Craig, premises (2)–(5) are relatively uncontroversial among philosophers, but "the epistemic entertainability of premise (1) (or its denial) does not guarantee its metaphysical possibility."<ref>{{cite book |author=Craig |first=William Lane |title=Reasonable faith |publisher=Crossway |year=2008 |isbn=978-1-4335-0115-9 |page=185 |quote=Premises (2)–(5) of this argument are relatively uncontroversial. Most philosophers would agree that if God's existence is even possible, then he must exist. ...the epistemic entertainability of premise (1) (or its denial) does not guarantee its metaphysical possibility.}}</ref> Furthermore the philosopher Richard M. Gale argued that premise three, the "possibility premise", [[begs the question]]. He stated that one only has the epistemic right to accept the premise if one understands the nested [[modal operator]]s, and that if one understands them within the system S5—without which the argument fails—then one understands that "possibly necessarily" is in essence the same as "necessarily".<ref>{{Cite book| title=On the Nature and Existence of God | first=Richard | last=Gale | publisher=Cambridge University Press | year=1993 | isbn=978-0-521-45723-1 |page=227}}</ref> Thus the premise begs the question because the conclusion is embedded within it. On S5 systems in general, James Garson writes that "the words ‘necessarily’ and ‘possibly’, have many different uses. So the acceptability of axioms for modal logic depends on which of these uses we have in mind."<ref>{{cite web | last=Garson | first=James | title=Modal Logic | website=Stanford Encyclopedia of Philosophy | date=2000-02-29 | url=https://plato.stanford.edu/archives/sum2014/entries/logic-modal/}}</ref> Summary: Please note that all contributions to Christianpedia may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here. You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see Christianpedia:Copyrights for details). Do not submit copyrighted work without permission! Cancel Editing help (opens in new window) Discuss this page