This is an extract of our Ontological Argument Notes document, which we sell as part of our Philosophy of Religion Notes collection written by the top tier of University Of Oxford students.
The following is a more accessble plain text extract of the PDF sample above, taken from our Philosophy of Religion Notes. Due to the challenges of extracting text from PDFs, it will have odd formatting:
The ontological argument Kant: ontology = arguing 'completely a priori, from mere concepts, to the existence of a supreme cause' Ontological arguments have no one specific form, but are a family of related arguments which argue from concepts and definitions rather than from observable facts about the known world. All ontological arguments propose that when we see what the concept of God amounts to or entails, we will see that God cannot fail to exist. That is to say, ontological arguments attempt to show that God is a necessary being, and that his non-existence is as absurd a concept as a four-sided triangle. Anselm - Descartes - Plantinga Anselm's ontological argument: reductio ad absurdum ('God' = that than which nothing greater can be conceived) (1) God exists in the understanding, but not in reality (2) Existence in reality is greater than existence in the understanding alone (3) God's existence in reality is possible (4) If God existed in reality, he would be greater than he is (from (1) and (2)) (5) Therefore, it is possible that a being exists which is greater than that than which nothing greater can be conceived. (5) is absurd and self-contradictory, therefore we can assert: (6) it is false that God exists in the understanding but not in reality and since God clearly does exist in the understanding, we can conclude: (7) God exists in reality.
Gaunilo's objection: Gaunilo attempts to show the absurdity of Anselm's argument by using the same method to prove the existence of something absurd, such as the 'greatest possible island'. (a) Gaunilo misquotes Anselm! Anselm is not arguing for the existence of a being that is in fact greater than all other beings, but for the existence of a being than which it is not possible that there be a greater. So Gaunilo's conclusion should merely have been that there is an island such that no other island is greater than it, which is not a controversial conclusion!
(b) the qualities that make an island great are qualities which have no intrinsic maximum. Number of palm trees, amount and quality of beaches or coconuts etc., are all qualities such that there is no quantity of them more than which it is impossible for an island to possess. This is not similarly true of Anselm's greatest possible being - supposing we can agree upon what we mean by omnipotence and omniscience, these are qualities that exemplify the 'intrinsic maximum' of 'knowledge' and 'power'. A better objection: Anselm wants to assert that existence is a 'great-making property' - a non-existent being would be greater if it did in fact exist. If we restructure the argument in terms of possible worlds, we can posit that Anselm means to suggest in premiss (2) that (2') 'for any being x and possible world W, if x does not exist in W, then there is a possible world W*
such that x is greater in W* than in W'. Premiss (4) thus becomes (4') 'if God does not exist in the actual world, there
Buy the full version of these notes or essay plans and more in our Philosophy of Religion Notes.