instead of arguing independently, why don;t we find the best arguments in the literature
ChatGPT said:
That’s a smart and constructive approach. Instead of reinventing the wheel or debating in circles, drawing from the best arguments in the literature—whether academic, philosophical, legal, scientific, or otherwise—can:
- Ground the discussion in well-reasoned, peer-reviewed thought.
- Save time by building on existing insights.
- Highlight the strongest positions on each side, including nuances and counterarguments.
- Elevate the quality of the conversation beyond personal opinion.
If you let me know the topic or question you’re focused on, I can help identify and summarize the most influential or well-regarded arguments from the relevant literature. We can compare the best pro and con positions or even build a structured debate format based on expert perspectives.
What topic are you interested in?
You said:
what is the best argument against plantinga’s argument for god
ChatGPT said:
Great question. Alvin Plantinga’s argument for God—most famously his Modal Ontological Argument and his Evolutionary Argument Against Naturalism (EAAN)—has drawn significant attention and criticism.
Let’s focus on the Modal Ontological Argument, since it’s perhaps his most influential argument for the existence of God.
Plantinga’s Modal Ontological Argument (Brief Summary)
Plantinga’s version uses modal logic and centers on the concept of a maximally great being (i.e. one that is omnipotent, omniscient, and morally perfect in all possible worlds).
The structure roughly goes:
- It is possible that a maximally great being exists.
- If it is possible, then it exists in some possible world.
- If it exists in some possible world, then it exists in every possible world.
- If it exists in every possible world, then it exists in the actual world.
- Therefore, a maximally great being exists.
It hinges critically on premise 1: that it’s possible for such a being to exist.
Best Argument Against Plantinga’s Ontological Argument
The Most Common and Powerful Objection: The Possibility Premise Is Question-Begging or Symmetrical
This comes from philosophers like Graham Oppy, Michael Tooley, and others.
The Objection:
Plantinga’s argument depends on the assumption that “a maximally great being is possibly instantiated.” But:
- Possibility cuts both ways. If it’s possible that a maximally great being exists, then it exists.
But if it’s possible that a maximally great being does not exist, then it necessarily does not exist (because necessary existence and nonexistence are modal opposites).
Therefore, one could simply mirror the argument:
- It is possible that a maximally great being does not exist.
- If it is possible, then it does not exist in some possible world.
- If it does not exist in some possible world, it does not exist in any possible world.
- Therefore, a maximally great being does not exist.
This shows that the argument doesn’t prove God’s existence, but rests entirely on which modal intuition (possibility or impossibility) you accept at the start. So it becomes a battle of intuitions, not a logical proof.
Graham Oppy’s Critique (Summarized)
Oppy has argued that:
- The Modal Ontological Argument is logically valid but dialectically ineffective.
- It presupposes a controversial modal claim (that the existence of a maximally great being is possible) that opponents do not grant.
- Hence, no one who doubts the conclusion should accept the first premise.
Supporting Concepts from Modal Logic
- In modal logic S5 (which Plantinga uses), if something is possibly necessary, then it is necessary.
- That’s powerful, but it also means you only need to reject the “possible” part of the first premise to avoid the conclusion.
Summary: Best Argument Against
The Modal Ontological Argument is question-begging: it front-loads its conclusion into its first premise by asserting that God’s existence is possibly necessary. But this is not a neutral or uncontroversial claim—it’s just as easy to assert the opposite. So the argument lacks persuasive power unless one already accepts its modal assumptions.
Would you like to also examine criticisms of Plantinga’s Evolutionary Argument Against Naturalism? It’s another area where rich counterarguments exist.
You said:
what about the objection that existence is not a property e.g. Kant, broad
ChatGPT said:
Excellent—yes, the “existence is not a property” objection is a deep and important one, and it directly targets ontological arguments in general, including Plantinga’s. This critique is often traced to Immanuel Kant, and it was later refined by philosophers like C.D. Broad and J.N. Findlay.
Let’s explore that objection carefully in the context of Plantinga’s Modal Ontological Argument (MOA).
Recap: Plantinga’s MOA in Brief
Plantinga doesn’t argue that existence is a property in the same way Descartes or Anselm might have. Instead, he argues that necessary existence is a great-making property, and a maximally great being is one that has necessary existence (exists in all possible worlds).
So he isn’t quite saying, “God exists, therefore God exists”—he’s saying:
“If it is possible that a necessarily existent being exists, then it exists in all possible worlds (including this one).”
Kant’s Objection: Existence Is Not a Real Predicate
The Classic Objection
Kant argued that:
Existence is not a real predicate—it doesn’t add anything to the concept of a thing.
For example, the concept of “100 real dollars” does not contain more content than the concept of “100 imaginary dollars.” The existence of the dollars doesn’t enhance their conceptual attributes; it just places them in reality.
Applied to God:
Saying “a maximally great being exists” doesn’t add to the greatness. It just asserts that the concept is instantiated. So existence cannot be a “great-making” property, which undermines the key move in Plantinga’s logic.
C.D. Broad’s Version: The Trouble With Necessary Existence
Broad (and also Findlay) adapted Kant’s idea in modal terms:
Necessary existence is not a property in the same way as omniscience or omnipotence.
To say a being exists necessarily is to quantify over possible worlds, not to add a feature to the being itself. But this treats necessity as semantic or logical, not as an ontological “greatness.”
So if existence—especially necessary existence—is not a real, positive property, then the definition of a “maximally great being” becomes suspect.
Why This Matters to Plantinga
Plantinga’s whole argument hinges on defining God as a necessarily existent maximally great being. If:
- Existence isn’t a property (Kant), and
- Necessary existence isn’t a genuine “great-making” feature (Broad),
then the concept of a “maximally great being” may be logically coherent but metaphysically empty—you can define it, but that doesn’t mean it corresponds to anything real.
This blunts the force of the Modal Ontological Argument because it shows the concept of “maximal greatness” may be built on questionable metaphysical assumptions.
Summary: The “Existence Is Not a Property” Objection
| Objection | Implication for Plantinga |
|---|---|
| Existence is not a real predicate (Kant) | Undermines the idea that necessary existence is a “great-making” property. |
| Necessary existence is not a metaphysical quality (Broad, Findlay) | Challenges the coherence of the “maximally great being” concept. |
| Conclusion | Even if logically valid, the MOA may rest on flawed assumptions about what it means to “exist” necessarily. |
Would you like a comparison between this objection and the “symmetry” objection (the one about modal intuitions cutting both ways)? They target different aspects of the argument.
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