Anselm's Ontological Argument

Anselm's ontological argument is a famous argument for the existence of God.
It's a great example of philosophical investigation, which seeks good reasons for beliefs through questioning.
The argument explores the nature of God, perfection, and existence and whether God exists.
While Anselm's original formulation may not be widely accepted today, it has had a significant impact on philosophy.
It led to insights into possibility, necessity, and perfection, which are crucial for conceptual analysis and argumentation.

The ontological argument led to new distinctions and key terms that are fundamental in philosophy.

A Priori Knowledge: Knowledge acquired independently of experience.
- Examples include knowledge of formal mathematics and logic.
- It relies on reasoning rather than sensory observation.
- Example: "A circle has no sides."
A Posteriori Knowledge: Knowledge derived from experience.
- It requires sensory input.
- Examples include knowing the color of a shirt or the current time.
- A posteriori knowledge is based on observations and empirical data.
The ontological argument is unique because it aims to prove God's existence a priori, without relying on sensory experience.
Saint Thomas Aquinas' arguments for God's existence, in contrast, are a posteriori.

Possible Worlds: Alternative ways the universe could be.
- They are used to conceptualize different scenarios or possibilities.
- Examples include worlds where historical events unfolded differently or where individuals have different characteristics.
Logical Possibility: Anything that can exist without a logical contradiction.
- It includes physical possibilities and scenarios that break the laws of nature but do not create contradictions.
- Examples: Flying to school, shrinking to a small size.
Logical Impossibility: Anything that contains a logical contradiction.
- Example: A round square.
- A round square is logically impossible because the definition of round contradicts the definition of square.

Necessary Existence: Something that must exist in every possible world.
- If it didn't exist, it would lead to a logical contradiction.
- Example: All circles are round; 1 + 1 = 2.
Contingent Existence: Something that exists in some worlds but not others.
- It exists in at least one possible world but not necessarily all of them.
- Contingent existence is usually a posteriori.
- Examples: Wearing a blue shirt, an individual's existence.
Anselm's ontological argument claims that God's existence is logically necessary.

The task is to think about the question using these key terms: possibility, necessity, contingency, a priori, a posteriori knowledge.
Think about the properties of the perfect professor in terms of necessity, possibility, a priori, and a posteriori.
Consider whether the idea of a perfect professor is logically possible or impossible.

The ontological argument for the existence of God by Saint Anselm of Canterbury:
- God is something than which nothing greater can be conceived. Even a fool (an atheist) can understand this concept.
- If something exists only in the understanding, then something greater can be imagined, i.e., something that exists in reality as well.
- Therefore, God must exist in reality; otherwise, God would not be the greatest thing that can be imagined.
Premise 1: God, by definition, is greater than anything that can be imagined.
Premise 2: Existence in reality and imagination is greater than existence in imagination alone.
Conclusion: If God did not exist, it would contradict the definition of God. Therefore, God must exist.

The argument relies on the understanding of a priori knowledge, possibility, necessity, and contingency.
It is an exercise in logical possibility, imagining the most perfect thing, which must exist in reality and thought.
Philosophical questions to consider:
- Is your understanding of God defined as that which nothing greater can be thought?
- Does the fool understand this definition?
- Do you have an understanding of all the properties of God on this definition?
- What would God be like?
Paradoxes arise when considering perfection, such as the Simpson's joke: "Could God microwave a burrito so hot that even he could not eat it?"
Consider whether it is more perfect for God to obey the laws of logic or to break them.
Think about the properties of perfection in terms of existing in reality and/or the mind.
Does there have to be a perfect professor in the real world in order for there to be a perfect professor. In order for the perfect professor to matter, must he exist on every possible world or just one.

Guanilo's Perfect Island Objection: A criticism of Anselm's argument is presented as a reductio ad absurdum.
The perfect island is by definition greater than any island that can be imagined.
Existence in reality and imagination is greater than existence in imagination alone.
Therefore, the perfect island exists.
This objection exposes potential problems with the assumptions behind Anselm's premises.
How can you use Guanilo's perfect island idea to object to one of Anselm's premises?
Discussion/Reflection Questions:
- Are you able to describe the perfect island?
- Is it an idea that exists in your understanding?
Consider whether the perfect island is even possible.
- Would the perfect island have a lot of people on it? Would it have no people on it?
Is premise two true for both things that exist necessarily as well as contingent things?
The islands are contingent. The island might exist, it might not exist.

Another ontological argument is presented for the devil:
- The devil is by definition greater than any evil that can be imagined.
- Existence in reality and imagination is greater than existence in imagination alone.
- Therefore, the devil exists.
This argument is not meant to be taken seriously but is used to pressure Anselm's argument.
In Christianity, there is no idea of the devil existing as an all-perfect evil.
Manichean dualism is a view of the universe that said that there are two forces that are equally powerful, the devil and god, an older version of Christianity before Catholicism.
The same kinds of questions are asked about the devil as were questions about the possible island. You're trying to come up with objections to these. You're using ideas like perfect island and perfect devil as ways to brainstorm the premise's flaws.

The purpose of the argument is not to prove or disprove God's existence.
It is an exercise in philosophical examination to uncover the main concepts, distinctions, and methodologies of philosophy.
This is done through philosophical examination of what is God, what is perfection, is it more perfect to exist than to not exist.
All of this comes together with the idea of asking: Does God exist?