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  • Created on: 17-04-16 11:59


Attempts to prove existence by reason alone

A priori - does not rely on evidence from senses, but on logical argument 

Produces conclusion which aims to be self-evidently true or logically necessary

Deductive - contains conclusion it reaches

Analytic - true by definition alone

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Anselm - P1

Anslem laid out argument in "Proslogion"

Aimed to prove existence by reducing to absurdity the oppositve, being that God does not exist

Therefore, wanted to show that God cannot not exist

Definition of God - "That than which nothing greater can be concieved"

"The fool" believes that it cannot be true

"Without a doubt, therefore, there exists, both in understanding and in reality, something htan which a greater cannot be thought"

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Anselm - P2

When we speak of God, we intuitively know what is meant by the term "God"

God is greater than all other beings in the sense that he is supremely perfect

"That than which nothing greater can exist" must possess all perfections

When we speak of God we speak of such a being 

If such a being posesses all perfections, must exist because existence is perfection

Must exist in re (in reality) 

It does not exist simply in the mind because what exists in reality is greater than what exists soley in the mind 
God is a necessary being 
Therefore, God's existence is de dicto (by definition) 

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Anselm - P3

Anselm is aware that existence of God is denied by atheists, and in response cites Pslam 53 - "the fool has said in his heart there is no God"

The Psalmists fool is the atheist who says what is impossible to say since it cannot be true - that God does not exist 

Anselm believes atheists say this because they have failed to understand the full implications of the concept of God - had they understood, impossible to deny existence

In order to deny, atheist must at least have concept of God in their understanding - then only a small step to recognising impossibility of denying existence of such being

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Strengths of Anselm

Deductive - holds out hope for proof - if valid, it will be proof for both believer and atheist

Starting point of argument is valid for both believer and atheist - definition of God as "that than which nothing greater can be concieved" is accepted by atheist even if they deny such being exists

Argument continues to be studied and debated - therefore reasonable to assume there are good reasons to consider argument to be sound in some way

The atheist must have some understanding of God in order to be able to reject belief 

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Weaknesses of Anselm

Idea of God being "that than which nothing greater can be concieved" - not coherent - how can he be omniscient? He can't know future human choices

Definition is mutually inconsistent- no being both omnipotent and omniscient - an omnipotent being could make creature who had a secret unknown to anyone but itself, while an omniscient being must know every secret 

Leads to useless God - supposing we can make sense of great properties and show them to be mutually consistent, the concept of God we will arrive at will be so distant from religious experience it will be useless

Cannot be assumed that this is the only logical way of defining God

Defining God and proving existence are2 different thigns - first doesn't lead to second - when we say existence is part of God's definition we are just saying that no non-existing being can be God

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Descartes overview

Supported ontological argument because it didn't rely on unreliable empirical evidence

Wanted believers to realise that when they used the word "God" they meant an infinetly perfect being superior to all beings in perfection

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I exist 
In my mind I have the concept of a perfect being 
As an imperfect being, I could not have conjured up the idea of a perfect being 
Therefore, the concept of a perfect being must have originated from a perfect being itself
A perfect being must exist in order to be perfect
Therefore, a perfect being exists

The idea of God is the idea of a supremely perfect being 
A suprememly perfect being has all perfections 
Existence is perfection
A perfect being has the perfection of existence
If God possesses the perfection of existence it is illogical to think of God as not existing 
God exists 

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Objected Anselm's argument 

Rejected view that human intellect alone could prove existence of God, claimed that:

Anselm was guilty of making transitional error - moving from definition to existence

Guilty of making assumption about definition of God - not all believers may share definition 

Aquinas believed that God's existence in reality must be demonstrated a posteriori (truth claims which come from experience and knowledge) 

However, Anselms' argument strong because he insists on God being without limits and non-contingent 
God's existence is by definition, not open to any kind of empirical proof, thus, being beyond proof is proof of existence 

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Demonstrated that if logic of ontological argument was applied to other things than God it would lead to invalid conclusions 

Replacing word God with "the greatest island" leads to argument which has same form but false conclusion 

I can concieve of an island greater than which no island can be thought
Such an island must possess all perfections 
Existence itself is a perfection
Therefore, the island exists

However, criticism exposed by Anselm who said his proof was:
Only intended to apply to necessary beings, not to contingent such as the island
Not understood by ahteists who have failed to understand the full implications of the concept of God

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Opposed view of Anselm that existence was necessary for perfection

This was called a predicate - something that is true without seeing or experiencing it 

Thus, if God had all perfections, then a predicate of God would be that he actually existed, however Kant observed:

Existence is not associated with the definition of something, since it did not add to our understanding of that thing

We must establish the existence of something before we can say what it is like, not the other way round 

We cannot ascribe exsitence a priori to our definiton of a perfect being 

"God is an object of pure thought" - Kant 

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Considered argument a failure because: 

Made false assumption about existence - that necessary exsitence was a coherent concept

Existence could only ever be contingent 

All things that could be said to exsit could also be said to not exist 

Existence is simply a matter of fact - no form of existence could be analytically true

It is not possible to move from a de dicto defintion of existence to a in re existence - only latter is verifiable 

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Argued that the very nature of God meant that if he didn't exist necessarily, then he did not exist at all 

Proposed form of the argument in support of necessary existence working on presumption that if God does exist, then he would:

God is that than which nothing greater can be thought
Necessary exsitence is perfection
If God possesses all perfections he must possess necessary existence
A necessary being cannot not exist 
If God could exist then he would exist necessarily
It is contradictory to sat thrat a necessary being does not exist 
God must exist

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Furthered argument claiming that since God is maximally great and perfect, then must exist in all possible worlds and will be same in each one of them

We are able to imagine any number of alternative worlds in which things may be quite different 

There must be any number of possible worlds, including our own

If God's exsitence is necessary, he must exist in them all and have characteristics of God in all

This is because God is maximally great and maximally excellent

Such a being would be omnipotent, omniscient and omnibenevolent in all worlds

"The greatest possible being must have maximal excellent in every possible world" - Plantinga

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Rejects argument as it has no basis in empirical fact or scientic observation and lacks "even a single piece of data from the real world"

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