Ontological argument

====Hartshorne and Malcolm====
[[Charles Hartshorne]] and [[Norman Malcolm]] are primarily responsible for introducing modal versions of the argument into the contemporary debate. Both claimed that Anselm had two versions of the ontological argument, the second of which was a modal logic version. According to James Harris, this version is represented by Malcolm thus:<blockquote>If it [that than which nothing greater can be conceived] can be conceived at all it must exist. For no one who denies or doubts the existence of a being a greater than which is inconceivable, denies or doubts that if it did exist its nonexistence, either in reality or in the understanding, would be impossible. For otherwise it would not be a being a greater than which cannot be conceived. But as to whatever can be conceived but does not exist: if it were to exist its nonexistence either in reality or in the understanding would be possible. Therefore, if a being a greater than which cannot be conceived, can even be conceived, it must exist.</blockquote>Hartshorne says that, for Anselm, "necessary existence is a superior manner of existence to ordinary, contingent existence and that ordinary, contingent existence is a defect." For Hartshorne, both Hume and Kant focused only upon whether what exists is greater than what does not exist. However, "Anselm's point is that what exists and cannot not exist is greater than that which exists and can not exist." This avoids the question of whether or not existence is a predicate.<ref name="auto"/>

Referring to the two ontological arguments proposed by Anselm in Chapters 2 and 3 of his ''Proslogion'', Malcolm supported Kant's criticism of Anselm's argument in Chapter 2: that existence cannot be a perfection of something. However, he identified what he sees as the second ontological argument in Chapter 3 which is not susceptible to such criticism.<ref name="Malcolm1960">{{harvnb|Malcolm|1960}}.</ref>

In Anselm's second argument, Malcolm identified two key points: first, that a being whose non-existence is ''logically'' impossible is greater than a being whose non-existence is logically possible, and second, that God is a being "than which a greater cannot be conceived". Malcolm supported that definition of God and suggested that it makes the proposition of God's existence a [[logical truth|logically necessarily true]] statement (in the same way that "a square has four sides" is logically necessarily true).<ref name="Malcolm1960" /> Thus, while rejecting the idea of existence itself being a perfection, Malcolm argued that ''necessary'' existence is a perfection. This, he argued, proved the existence of an unsurpassably great necessary being.

Jordan Sobel writes that Malcolm is incorrect in assuming that the argument he is expounding is to be found entirely in Proslogion chapter 3. "Anselm intended in Proslogion III not an independent argument for the existence of God, but a continuation of the argument of Proslogion II."<ref>{{cite book | title=Logic and theism: arguments for and against beliefs in God | publisher=Cambridge University Press | author=Sobel, Jordan Howard | year=2004 | pages=81–82 | isbn=978-0-521-82607-5|url=https://books.google.com/books?id=ZQh8QJOQdOQC&q=%22his+existence+is+necessary%22}}</ref>