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3 Dec 2025

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Understanding the Ontological Argument for God's Existence

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Zoe @zoe_b8

The Ontological Argument attempts to prove God's existence through pure reason rather than observation. This philosophical approach argues... Show more

Ontological argument-> ANSELM/DESCARTES/ KANT (EXISTENCE IS NOT A PREDICATE) / GAUNILO(ISLAND)
Inductive argument by which intends to guaran

The Ontological Argument Key Proponents and Critics

Anselm's argument begins with defining God as "a being than which nothing greater can be conceived." If God exists only in our minds, he can't be truly greatest - as something existing in reality would be greater. Therefore, for God to be the greatest conceivable being, He must exist in reality, not just in our thoughts. Anselm believed God's existence is a necessary truth rather than a contingent one.

Gaunilo challenged this reasoning with his famous "perfect island" counterargument. He proposed imagining "an island than which no greater island can be conceived." Following Anselm's logic, this perfect island must exist in reality - revealing the structural flaw in the argument. Anselm responded that islands are contingent beings (dependent on other things), while God alone possesses necessary existence.

Descartes supported Anselm, defining God as "the supremely perfect being" who must possess all perfect attributes, including existence. He argued that denying God's existence is as contradictory as imagining "a mountain without a valley" - it simply cannot be done. Meanwhile, Kant strongly opposed this view, arguing that existence is not a predicate (characteristic) that adds to a definition. To say "God exists" adds nothing to our understanding of God's essence.

Remember this! The ontological argument is deductive rather than inductive. This means if all its premises are true, the conclusion must be true - offering potential certainty rather than just probability.

Ontological argument-> ANSELM/DESCARTES/ KANT (EXISTENCE IS NOT A PREDICATE) / GAUNILO(ISLAND)
Inductive argument by which intends to guaran

Strengths and Limitations of the Ontological Argument

The ontological argument doesn't rely on empirical evidence, which some philosophers consider an advantage. While our senses might deceive us (as Plato argued), knowledge gained through pure reason could be more reliable. If successful, this argument would provide absolute proof of God's existence rather than just probability.

However, the argument faces significant limitations. Anselm himself acknowledged that "belief precedes understanding" - suggesting his argument works best within a theistic language game where certain religious assumptions are already accepted. Even many religious philosophers don't accept Anselm's definition, as it only appeals to those who already share his conception of God.

Kant identified perhaps the most damaging critique when he pointed out the argument omits the word "if." He suggested it should be phrased "if there is a God, then God will exist necessarily." While the statement "God exists necessarily" may follow from Anselm's definition, this doesn't prove God actually exists in reality. As Kant famously argued, you cannot simply define something into existence.

Think about it Is it possible to prove anything exists using only definitions and logic, without any reference to the real world? This question reveals why the ontological argument remains controversial.

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Basil

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This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

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Sudenaz Ocak

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In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

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very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

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I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.

Xander S

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THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

Best app on earth! no words because it’s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user

 

Religious Studies

157

3 Dec 2025

2 pages

Understanding the Ontological Argument for God's Existence

user profile picture

Zoe

@zoe_b8

The Ontological Argument attempts to prove God's existence through pure reason rather than observation. This philosophical approach argues that once God is correctly defined, His existence becomes logically necessary - similar to how a triangle must have three angles by... Show more

Ontological argument-> ANSELM/DESCARTES/ KANT (EXISTENCE IS NOT A PREDICATE) / GAUNILO(ISLAND)
Inductive argument by which intends to guaran

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The Ontological Argument: Key Proponents and Critics

Anselm's argument begins with defining God as "a being than which nothing greater can be conceived." If God exists only in our minds, he can't be truly greatest - as something existing in reality would be greater. Therefore, for God to be the greatest conceivable being, He must exist in reality, not just in our thoughts. Anselm believed God's existence is a necessary truth rather than a contingent one.

Gaunilo challenged this reasoning with his famous "perfect island" counterargument. He proposed imagining "an island than which no greater island can be conceived." Following Anselm's logic, this perfect island must exist in reality - revealing the structural flaw in the argument. Anselm responded that islands are contingent beings (dependent on other things), while God alone possesses necessary existence.

Descartes supported Anselm, defining God as "the supremely perfect being" who must possess all perfect attributes, including existence. He argued that denying God's existence is as contradictory as imagining "a mountain without a valley" - it simply cannot be done. Meanwhile, Kant strongly opposed this view, arguing that existence is not a predicate (characteristic) that adds to a definition. To say "God exists" adds nothing to our understanding of God's essence.

Remember this! The ontological argument is deductive rather than inductive. This means if all its premises are true, the conclusion must be true - offering potential certainty rather than just probability.

Ontological argument-> ANSELM/DESCARTES/ KANT (EXISTENCE IS NOT A PREDICATE) / GAUNILO(ISLAND)
Inductive argument by which intends to guaran

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

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Strengths and Limitations of the Ontological Argument

The ontological argument doesn't rely on empirical evidence, which some philosophers consider an advantage. While our senses might deceive us (as Plato argued), knowledge gained through pure reason could be more reliable. If successful, this argument would provide absolute proof of God's existence rather than just probability.

However, the argument faces significant limitations. Anselm himself acknowledged that "belief precedes understanding" - suggesting his argument works best within a theistic language game where certain religious assumptions are already accepted. Even many religious philosophers don't accept Anselm's definition, as it only appeals to those who already share his conception of God.

Kant identified perhaps the most damaging critique when he pointed out the argument omits the word "if." He suggested it should be phrased: "if there is a God, then God will exist necessarily." While the statement "God exists necessarily" may follow from Anselm's definition, this doesn't prove God actually exists in reality. As Kant famously argued, you cannot simply define something into existence.

Think about it: Is it possible to prove anything exists using only definitions and logic, without any reference to the real world? This question reveals why the ontological argument remains controversial.

We thought you’d never ask...

What is the Knowunity AI companion?

Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.

Where can I download the Knowunity app?

You can download the app from Google Play Store and Apple App Store.

Is Knowunity really free of charge?

That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.

2

Smart Tools NEW

Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines

Mock Exam
Quiz
Flashcards
Essay

Most popular content: Philosophy of Religion

Most popular content in Religious Studies

Most popular content

Can't find what you're looking for? Explore other subjects.

Students love us — and so will you.

4.9/5

App Store

4.8/5

Google Play

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

Best app on earth! no words because it’s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

Best app on earth! no words because it’s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user