Date of Publication


Document Type

Master's Thesis

Degree Name

Master of Arts in Philosophy

Subject Categories


Thesis Adviser

Jeremiah Joven Joaquin

Defense Panel Chair

Maxell Aranilla

Defense Panel Member

Lorenz Moises Festin
Napolelon Mabaquiao, Jr.


A recent debate on Alvin Plantinga’s refutation on Gaunilo’s parody the perfect island has brewed a relatively new development of discussing the ontological argument which focuses on the concept of perfection as applied to the notions of God and the perfect island. The thesis’ purpose is primarily to investigate Plantinga’s stand that the idea of the perfect island is not a parallel argument to the concept of God due to its non-maximal qualities. This leads to the impossibility of conceiving the perfect or greatest possible island. As the paper claims that St. Anselm’s ontological argument and Gaunilo’s parody are parallel, the research puts forward a clear distinction of both arguments by showing their fundamental difference following Graham Oppy’s formulations of the arguments. This research provides a comprehensive scrutiny on the validity of both arguments using Plantinga’s concept of logical possibility. Following St. Anselm’s form of argumentation, the two arguments are both valid yet Gaunilo’s parody principally serves as a disanalogy to St. Anselm’s ontological argument. Further, it gives a detailed analysis of Brian Garrett’s and Milo Crimi’s assertion that the perfect island’s properties are maximal by explicitly defining the idea of an island as any island exhibiting an ideal ratio of its great-making island properties. Their claim presupposes multitude perfect islands. Hence, the assumption is a contradiction to the definition of God as the only Being who possesses the absolute, maximum perfection of goodness. The resolution of the main problem is done through the use of St. Thomas Aquinas’ fourth cosmological argument, the degrees of perfection. This is indispensable in the assessment of Gaunilo’s parody on why it is incompatible to St. Anselm’s ontological argument. It is also use to evaluate proponents of Gaunilo’s parody particularly Garrett’s and Crimi’s positions. The thesis’ conclusion demonstrates the success of Plantinga’s criticism which is advanced by Danielyan. Its success is supported by St. Thomas’ degrees of perfection argument. In the end, Gaunilo’s parody is a disanalogy to St. Anselm’s ontological argument since it does not stay faithful to its definition of a perfect island as an island than which no greater island can be conceived. The concept perfection as applied to the concept of an island is incoherent due to the relative notion of perfection which results to the existence of multitude perfect islands.

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Accession Number



Perfection; God—Proof from grades of perfection

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