Ontological arguments (Arabic: البرهان الوجودي) refer to some of the philosophical arguments for the existence of God which are based on some conceptual definitions of Him. The first ontological argument, in Christian tradition, was proposed by Anselm of Canterbury, the famous theologian of the middle ages. Some subsequent Christian philosophers (such as René Descartes, Gottfried Leibniz, Alvin Plantinga, etc.) continued to develop the argument and presented some new versions of it. Likewise, some Shi'a scholars (such as, Mulla Sadra and Muhammad Husayn Isfahani) quite separately have proposed some accurate versions of various ontological arguments.
The first ontological argument was proposed by the famous Christian theologian and philosopher, Anselm of Canterbury in his Proslogion. Simultaneously, some of his contemporary scholars opposed him and his argument. But, some of the other theologians tried to defend of his argument.
Afterwards, subsequent philosophers presented the same versions of this proof. Some of the most important defenders of this argument are René Descartes and Alvin Plantinga. Moreover, some of the strong opponents of this argument are Thomas Aquinas (1225–1274) and Immanuel Kant.
Likewise, we see some similar arguments which are quite separately proposed by some classical Muslim philosophers like Avicenna, Mulla Sadra and some contemporary Muslim scholars such as Muhammad Husayn Isfahani.
Anselm's argument can be summarized as follows:
- We are told, God is the greatest and most perfect being which no greater can be conceived.
- If we suppose that there is no God, in reality, it means that this being exists just in our minds.
- The being which exists just in our mind is less perfect than the being which exists both in the mind and reality.
- Then, if there would be no God in reality, it equals the fact that God is not the greatest and most perfect being; and it is contradicts our presupposition which is mentioned in the first line. (See: proof by contradiction)
- Therefore, God exists in reality.
Muhammad Husayn al-Isfahani's Argument
Isfahani has presented his argument as follows:
- What unconditionally comes to existence by itself is the necessary being (Transcendent God).
- He, by his essence signifies his essence; and he is the most truthful evidence for his existence.
- Every sound and precise mind judges that if there would not be any extension for the necessary being in the universe then it would be just a conceptual notion.
- This being unexemplified is whether because of his being impossible existent, which contradicts our prime assumption [that it is a necessary being not an essential impossible one];
- Or because of his requirement of a cause, which contradicts our assumption. [because according to our prime assumption it is a necessary being and not contingent one] so he doesn't need to a cause and it is impossible too;
- So, deep contemplation on the meaning of the necessity results in the favorable conclusion.
According to al-Isfahani's argument, it is impossible for a necessary being that would be nonexistent; and he claims that the contemplation on the concept of the necessary being leads us to the fact that it would exist in the universe. He presents a deductive reasoning (modus ponendo ponens) to prove his claim: If this concept is just in the mind without any objective extension, then this being nonexistent has no reason but the two reasons which both of them are rejected; so this concept has certainly an objective extension. In other words, if there is an unexemplified concept - that is, its extension doesn't come to existence - this being unexemplified has no reason but these two ones:
- It is an essential impossible concept which doesn't come to existence and could never have any extension.
- It is not an essential impossible concept but instead it is a contingent being which needs to have a cause to come to existence.
And both of them are obviously false. Because, according to the definition, necessary being not just can comes to existence –so, it is not an essential impossible being- but it independently and unconditionally comes to existence by itself- so, it is not a contingent being.
Therefore, exact survey of the concept of necessary being leads us to its objective existence.
The most crucial object to ontological arguments is its being as a fallacious argument. The critics indicate that there is ad hominem fallacy in this argument. It means that there is no relation between the mind and reality in this regard. So, the attention to some conceptual notion can never lead us to some factual objects.
The critics mention the notion of "God's partner" as a counter example to this argument. They state that we can apply the same argument for the existence of God's Partner.
- God's partner is the greatest and most perfect being which no greater can be conceived.
- If we suppose that there is no God's partner in the reality, it means that this being exists just in mind.
- The being which exists just in mind is less perfect than the being which exists both in the mind and reality.
- Then, if there would be no God's Partner in reality, it equals to the fact that God's Partner is not the greatest and most perfect being; and it is contradicts our presupposition which is mentioned in the first line.
- Therefore, God's partner exists in reality.
But, this conclusion is intellectually impossible and obviously false.
- Ḥāʾirī Yazdī, Kāvushhāyi ʿql-i nazarī, p. 328-329.
- John Hick, An Interpretation of Religion, p. 75-79.
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- Ḥāʾirī Yazdī, Mahdī. Kāvushhāyi ʿql-i nazarī. Tehran: Muʾassisa-yi Pazhūhishī-yi Ḥikmat wa falsafa-yi Iran, 1384 SH.
- Hick, John. An Interpretation of Religion, New Haven/London, 1989.