Introduction to Arguments Based on Reason
Welcome to one of the most fascinating (and head-scratching!) chapters in your Religious Studies course. So far, you may have looked at arguments for God based on observation—like looking at the complexity of a watch or the start of the universe. This chapter is different. Here, we look at the Ontological Argument. This is an a priori argument, which means it is based on reason alone, rather than looking at evidence in the physical world.
Quick Tip: Think of this like a mathematical equation. You don't need to go outside to prove that \(2 + 2 = 4\); you just need to understand what the numbers mean. The Ontological Argument claims that if you truly understand the definition of "God," you will see that He must exist.
1. St Anselm of Canterbury
Anselm was an 11th-century monk who wanted to show that faith and reason work together. His argument is found in his book, the Proslogion.
The Definition of God
Anselm starts with a specific definition: God is "that than which nothing greater can be conceived".
In simpler terms: God is the greatest possible thing you could ever imagine. If you can think of something better than God, then that thing would be God instead!
Proslogion 2: Existence is a Greatness
Anselm argues that there is a difference between existing in the mind (in intellectu) and existing in reality (in re). He uses a logic that looks like this:
1. We can all understand the definition of God as the "greatest conceivable being."
2. Even a "fool" (an atheist) has this concept in their mind.
3. It is "greater" to exist in reality than to exist only in the mind.
4. Therefore, if God only existed in the mind, we could imagine something even greater: a God who exists in reality.
5. Since God is the greatest thing imaginable, He must exist in reality.
Proslogion 3: Necessary Existence
Anselm took this further. He argued that God doesn't just exist; He has necessary existence.
Most things (like us, trees, or cars) are contingent—we might exist, or we might not. But Anselm argued that a being that cannot be thought of as not existing is greater than one that can. Therefore, God must have necessary existence.
Key Takeaway: For Anselm, existence is a "perfection" or a "greatness." Since God is perfectly great, He cannot lack existence.
2. Challenges to Anselm: Gaunilo of Marmoutiers
Don't worry if Anselm's logic feels like a bit of a "word trick"—a fellow monk named Gaunilo felt the same way! He wrote a response titled "On Behalf of the Fool."
The "Lost Island" Analogy
Gaunilo used a reductio ad absurdum (reducing an argument to absurdity) to show that Anselm's logic was flawed. He asked us to imagine the most perfect island imaginable:
1. I can conceive of a "Perfect Island" (the greatest possible island).
2. It is better for an island to exist in reality than just in my mind.
3. Therefore, this "Perfect Island" must exist in reality.
Gaunilo points out that we know this is silly—you can't just "define" an island into existence! He argued that you cannot move from a definition in the mind to existence in the world without evidence.
Did you know? Anselm actually replied to Gaunilo! He argued that the logic only works for God because God is unique and necessary, whereas islands are contingent and can always be improved (e.g., you can always add one more coconut tree to make an island "better").
3. Challenges to Anselm: Immanuel Kant
Centuries later, the philosopher Immanuel Kant provided what many consider the "knockout blow" to the Ontological Argument. He had two main criticisms:
Criticism 1: Existence is not a Predicate
A predicate is a word that describes something (like "blue," "tall," or "powerful"). Predicates add to our understanding of what a thing is.
Kant argued that existence is not a predicate because saying "it exists" adds nothing to the description of the object.
Example: Imagine a "Golden Mountain." If I tell you it is "tall" and "shiny," I am adding predicates. If I then say "it exists," I haven't changed the description of the mountain; I've just told you there is an example of it in the real world.
Criticism 2: The 100 Thalers (Coins)
Kant used the example of \(100\) thalers (Prussian coins). He said that \(100\) real thalers have the exact same number of thalers and the same properties as \(100\) imaginary thalers.
In his words: "The real contains no more than the merely possible."
Because existence doesn't make the concept of God any "greater," Anselm's argument that "existence is a greatness" falls apart.
Key Takeaway: Kant believed that existence can only be proven through experience (a posteriori), not through definitions (a priori).
Summary and Common Mistakes
Quick Review Box
Anselm: Defined God as the "greatest conceivable being." Argued that existence is a "greatness," so God must exist.Gaunilo: Used the "Perfect Island" to show you can't define things into existence.
Kant: Argued that "existence is not a predicate" and used the \(100\) thalers example to show existence doesn't add to a concept.
Common Mistakes to Avoid:
1. Confusing "A Priori" and "A Posteriori": Remember, this argument is a priori. It does NOT use evidence from the world. If you start talking about the design of the universe, you are accidentally writing about the Teleological argument!
2. Misunderstanding Kant: Students often think Kant said God doesn't exist. He didn't! He just said that the Ontological Argument doesn't work as a logical proof.
3. Forgetting "Necessity": Don't forget Proslogion 3. Anselm's argument is stronger when you mention that God's existence is necessary, not just like a normal object.
Note: This chapter focuses specifically on the logic of reason. For arguments based on looking at the world, see the chapter "Arguments based on observation."