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Ontological argument

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An ontological argument is a deductive philosophical argument used to support the existence of God.

Anselm-CanterburyVit
Anselm-CanterburyVit

These arguments are based on ontology, which is the study of being or existence. Most ontological arguments are considered a priori. This means they rely on reasoning that comes from the organization of ideas rather than from physical observation. If the logical structure of these ideas is true, then God must exist. This makes the argument a purely conceptual way to explore the nature of reality.

One of the most famous mechanisms involves the concept of greatness.

Anselm-CanterburyVit
Anselm-CanterburyVit

St. Anselm of Canterbury formulated this in his 1078 work, the Proslogion. He defined God as a being than which no greater can be conceived. Anselm argued that even a person who denies God must have this concept in their mind. He suggested that if this greatest being exists only in the mind, it is not truly the greatest. A being that exists in both the mind and in reality is greater than one that exists only in the mind. Therefore, to be the greatest possible being, God must exist in reality.

In his third chapter, Anselm added a layer regarding necessity. He argued that a being that necessarily exists in reality is greater than one that does not. If the greatest possible being could be conceived not to exist, then a greater being would be possible. That greater being would be one that exists necessarily. Because we cannot imagine anything greater than God, God must exist necessarily. This approach uses a method called reductio ad absurdum. It shows that a specific idea leads to a contradiction if it is not true.

Different thinkers have developed various types of ontological arguments.

Avicenna Bust, left profile
Avicenna Bust, left profile

Ibn Sina, also known as Avicenna, developed the "Proof of the Truthful" in the early 11th century. His argument used the concepts of contingency and necessity. He argued that all "possible beings" require a cause for their existence. This chain of causes must end in a "Necessary Existent," or Wajib al-Wujud. This is a being that exists by its own essence. Other types of arguments include modal arguments, which look at possibility, and definitional arguments, which rely on definitions.

Frans Hals - Portret van René Descartes
Frans Hals - Portret van René Descartes

The history of these ideas spans many centuries and cultures. Before Anselm, the Islamic philosopher Ibn Sina provided a systematic logical derivation. In the 17th century, René Descartes proposed that God's existence is inferable from a clear and distinct idea of perfection. Gottfried Leibniz later tried to prove that a supremely perfect being is a coherent concept. In the 20th century, Kurt Gödel used modal logic in private notes to form an argument.

AlvinPlantinga
AlvinPlantinga

More recently, Alvin Plantinga proposed an alternative version based on modal logic.

David Hume
David Hume

Many philosophers have offered significant criticisms to these arguments. Gaunilo of Marmoutiers used the analogy of a perfect island to parody Anselm. He suggested the logic could be used to prove the existence of anything. Thomas Aquinas rejected the argument because he believed humans cannot truly know God's nature. David Hume argued that nothing can exist necessarily based on empirical reasoning.

Immanuel Kant - Gemaelde 2
Immanuel Kant - Gemaelde 2

Immanuel Kant claimed that "existence" is not a predicate. He argued that saying something exists adds nothing to its essence or perfection.

These debates connect to broader fields like logic, metaphysics, and the philosophy of religion. Philosophers like Graham Oppy have worked to classify these arguments into subcategories. These include mereological arguments, which look at the relation between parts and wholes. They also include experiential arguments, which focus on those who have had experiences of God. Whether through automated theorem provers or complex modal logic, the ontological argument remains a central topic in human thought.

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Littlemore.jpg
File:Avicenna Bust, left profile.jpg
Avicenna Bust, left profile.jpg
File:Anselm-CanterburyVit.jpg
Anselm-CanterburyVit.jpg
File:Frans Hals - Portret van René Descartes.jpg
Frans Hals - Portret van René Descartes.jpg
File:Gottfried Wilhelm Leibniz, Bernhard Christoph Francke.jpg
Gottfried Wilhelm Leibniz, Bernhard...
File:AlvinPlantinga.JPG
AlvinPlantinga.JPG
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David Hume.jpg
File:Immanuel Kant - Gemaelde 2.jpg
Immanuel Kant - Gemaelde 2.jpg
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