Ontological Argument
In the philosophy of religion, an Ontological argument is a deductive philosophical argument, made from an ontological basis, that is advanced in support of the existence of God. Such arguments tend to refer to the state of being or existing. More specifically, ontological arguments are commonly conceived a priori in regard to the organization of the universe, whereby, if such organizational structure is true, God must exist.
The first ontological argument in Western Christian tradition was proposed by Saint Anselm of Canterbury in his 1078 work, Proslogion (Latin: Proslogium, lit. ‘Discourse [on the Existence of God]’), in which he defines God as “a being than which no greater can be conceived,” and argues that such a being must exist in the mind, even in that of the person who denies the existence of God. From this, he suggests that if the greatest possible being exists in the mind, it must also exist in reality, because if it existed only in the mind, then an even greater being must be possible—one who exists both in mind and in reality. Therefore, this greatest possible being must exist in reality. Similarly, in the East, Avicenna’s Proof of the Truthful argued, albeit for very different reasons, that there must be a “necessary existent”.
Seventeenth-century French philosopher René Descartes employed a similar argument to Anselm’s. Descartes published several variations of his argument, each of which center on the idea that God’s existence is immediately inferable from a “clear and distinct” idea of a supremely perfect being. In the early 18th century, Gottfried Leibniz augmented Descartes’ ideas in an attempt to prove that a “supremely perfect” being is a coherent concept. A more recent ontological argument came from Kurt Gödel, who proposed a formal argument for God’s existence. Norman Malcolm also revived the ontological argument in 1960 when he located a second, stronger ontological argument in Anselm’s work; Alvin Plantinga challenged this argument and proposed an alternative, based on modal logic. Attempts have also been made to validate Anselm’s proof using an automated theorem prover. Other arguments have been categorised as ontological, including those made by Islamic philosophers Mulla Sadra and Allama Tabatabai.
Just as the ontological argument has been popular, a number of criticisms and objections have also been mounted. Its first critic was Gaunilo of Marmoutiers, a contemporary of Anselm’s. Gaunilo, suggesting that the ontological argument could be used to prove the existence of anything, uses the analogy of a perfect island. Such would be the first of many parodies, all of which attempted to show the absurd consequences of the ontological argument. Later, Thomas Aquinas rejected the argument on the basis that humans cannot know God’s nature. David Hume also offered an empirical objection, criticising its lack of evidential reasoning and rejecting the idea that anything can exist necessarily. Immanuel Kant’s critique was based on what he saw as the false premise that existence is a predicate, arguing that “existing” adds nothing (including perfection) to the essence of a being. Thus, a “supremely perfect” being can be conceived not to exist. Finally, philosophers such as C. D. Broad dismissed the coherence of a maximally great being, proposing that some attributes of greatness are incompatible with others, rendering “maximally great being” incoherent.
Contemporary defenders of the ontological argument include Alvin Plantinga, Yujin Nagasawa, and Robert Maydole.
The ontological argument is a deductive and a priori argument for the existence of God. It attempts to prove God’s existence through logical reasoning and analysis of the Concept of God, rather than relying on empirical evidence or observation of the world.
- Deductive Argument: The ontological argument uses deductive reasoning, meaning it starts with premises assumed to be true and uses logic to arrive at a necessary conclusion. If the premises are true, the conclusion must be true.
- A Priori Argument: Unlike a posteriori arguments (which rely on experience), the ontological argument is a priori. This means its premises are thought to be knowable independent of any sensory experience or observation of the world. It relies on reason and understanding of concepts.
- Focus on Definition: The core of the ontological argument lies in the definition of God. It suggests that the very concept or definition of God, as a being of unsurpassable perfection, necessarily implies God’s existence.
- Necessary Existence: A key element is the idea of “necessary existence.” If God is the greatest conceivable being, and existence is a perfection, then God must exist not just contingently (like things in the world that might not have existed), but necessarily (in all possible worlds).