Plantinga is best-known for his defence of the view that...

Plantinga is best-known for his defence of the view that religious belief is foundational, i.e. that religious belief does not stand in need of external justification, but is also known for his work on modal logic, i.e. on the logic of possibility and necessity. Plantinga applies his approach to modal logic to the ontological argument, presenting it in a revised form. The critics of the ontological argument are no less distinguished than are its advocates. Among them is St.

Thomas Aquinas, the thirteenth century Dominican and the greatest philosopher of religion of all. Aquinas was canonised in the fourteenth century, when he was said by the Pope to have met the criterion for canonisation of having performed three miracles in virtue of the answers that he had given to perplexing philosophical questions about God. Aquinas rejected the ontological argument in his Summa Theologica, First Part, Question Two.

The earliest critic of the ontological argument, though, was a contemporary of Anselm, the monk Gaunilo of Marmoutier. Gaunilo objected to the ontological argument on the ground that it seemed possible to use its logic to prove the existence of any perfect thing at all. Gaunilo sought to demonstrate this by constructing an ontological argument for the existence of the perfect island.

This argument, he suggested, is clearly fallacious, and so the ontological argument for the existence of God, which relies on precisely the same logic, must be fallacious too. The most vaunted criticisms of the ontological argument, however, are those of Immanuel Kant.

Kant argued against the ontological argument on the grounds that existence is not a property of particulars but a property of concepts, and that whatever ideas may participate in a given concept it is a further question whether that concept is instantiated. Whether his criticisms are sufficient to undermine all forms of the ontological argument remains a matter of much dispute. h of these things. There are also other, more cynical ways in which we can exercise control over our beliefs.

Using the techniques of hypnosis it is possible to induce beliefs in a subject without any regard for evidence at all. If one were thoroughly convinced of Pascal’s Wager, therefore, then one might choose to exercise control over one’s beliefs by hiring a hypnotist. There are, then, some things that we can do to influence our beliefs even if doxastic voluntarism is false.