The ontological argument...

Anselm defined God as "a being that which no greater can be conceived", and argued that this being must exist in the mind, even in the mind of the person who denies the existence of God. He suggested that, if the greatest possible being exists in the mind, it must also exist in reality because if it exists only in the mind, then an even greater being must be possible—one which exists both in the mind and in reality. Therefore, this greatest possible being must exist in reality.

---- From Wikipedia

The first issue I have with this argument is the use of the word "being". Is a being a conscious creature? Is a being a sentient thing? Is a being a type of person? Is a being an alien? Anyway...

The use of the term "greater" is an issue as well. The term greater makes no sense by itself. Greater than what? Greater just means bigger or better or more, which all require context. There has to be a standard to refer to. Maybe Anselm created this context in his works and defined a standard "being" in which to compare his notion of a greater being and then went so far as to infinitely extend the idea until he just ended with the word God. As in the same God that is the vague term used to describe any unknown or unknowable thing personified as an agent.

Essentially the argument is...

If I can think about something it can exist outside the mind if I just ad the word "better" to it. With the word better I can argue that it is better to exist outside the mind and therefore if a thing I think about is the best of its category (for example a "being") then it must exist because it would be better to have that thing in existence outside the mind than limited to just inside the mind.

This argument is shit. It allows for existence to arise from thoughts alone and for anything thought of to exist in reality.

Example: If I can think of the best guitar and it exists in my brain then the best guitar must exist in reality because the best guitar is only made the best by existing outside the brain. Because it is better to exist then to simply be imagined. But the concept of better and the concept of existence have little to do with each other.

Something can exist without being better than anything else. Being better only occurs when comparing two things and not all things require comparison to understand. It can simply have a purpose or a relationship with other things or it might be something that simply exists with no discernable interaction with anything you understand. Maybe you see a cloud a few miles away. It makes no difference to you in any practical way but you see it and it exists. It is not better or worse than anything. It's just a noteworthy cloud.

Any argument that puts human consciousness as the basis for reality seems needlessly vain. The idea that nothing would exist without humans is ridiculously presumptuous because it presumes that before humans existed there was nothing. This is stupid. Before you existed plenty of things existed. Unless you don't believe that things exist outside of your mind. If you think that the only existence that exists is the existence of thoughts and that you have a singular existential experience and that is what matters seems too insular. The history of life is the history of interaction. From when single cells began to combine with each other all biology has been an interconnected network of communication, metabolism, and other ecological concepts. To distill all of existence to what exists in human minds seems limited.

Humans attempt to describe reality based on their sensory and communicative capabilities. Because humans observe reality and have the ability to see themselves as a part of that reality they can describe themselves in the same way they describe other things. Just because you exist and your brain exists doesn't mean that something you thought of exists outside your synapses. I would imagine that it would be easier to think of things that don't exist rather than think of things that do exist. Even if you had a complete list of things that actually exist in the universe you could still think of combinations or exaggerations of those things that would exponentially increase the things you can think about. Most of those things would not exist.

For example: If I know of all the animals that exist I can imagine each of those animals with a chair growing out of their back and I just doubled the amount of bullshit in my head but that doesn't mean that each animal exists with a chair growing out of its back in reality. It makes no sense. Being able to think about something or imagine something has almost no relation to what actually exists in the world.

It seems like ontological arguments are actually just arguments designed to satisfy an already-held view. It puts too much value on cognitive capacities and conjures up reality out of thin air which is not scientific or rational. If one wants to justify their irrational beliefs one can use the ontological argument.

I'm reminded of the argument, "I think, therefore I am." The problem with this is that in isolation you can't really determine that you exist scientifically. There is nothing to test against. You need others to verify a hypothesis and engaging in experiments. I think that if others think you exist and you can interact with external objects then you probably exist. Or at least exist in some context.

The concept of God exists but that doesn't mean that there is a perfect "being" running around doing things.