Ontological arguments

Anselm’s first argument:

  1. God is that which nothing greater can be conceived.

  2. It is greater to exist in reality than merely as an idea in the mind

  3. If God does not exist, we can conceive of an even greater being, one that DOES exist.

  4. Therefore, God must indeed exist in reality.

Guanilo’s response:

  1. The Perfect Island is that island than which no greater can be conceived.

  2. It is greater to exist in reality than merely as an idea.

  3. If the Perfect Island does not exist, one can conceive of an even greater island, that is one that does exist.

Conclusion 1: Therefore, according to Anselm’s reasoning, the Perfect Island exists in reality.

  1. We do not think the Perfect Island actually exists in reality.

Conclusion 2: Therefore Anselm’s line of reasoning must be faulty

Reductio ad absurdum method = argument must be false because of absurdities that result if followed.

It is sometimes seen as a way of ‘ridiculing’ an argument.

Anselm’s response to Guanilo:

P1: We can imagine, if we try, a being that cannot possibly not exist (a necessary being)

P2: We can also imagine a being that can possibly not exist (a contingent being)

P3: A necessary being is greater than a contingent being.

P4: God is that which nothing greater can be conceived.

Conclusion: Therefore, God is a being that cannot possibly not exist, and therefore God exists, necessarily.

Anselm:

  • ANY perfect island is contingent - it comes into being and may cease to exist

  • The concept of God as the ‘greatest being’ entails that God must have ‘superior’ existence.

  • This (unique) necessary existence is only applicable to God because only God (That that which nothing greater can be conceived) cannot be imagined to exist.

Aquinas’ criticisms:

1) Human reason is fallible - we can get things wrong when we use our human reasoning, so a priori knowledge can be wrong.

2) God is transcendent (is above and beyond human understanding) and therefore we cannot fully comprehend or even define God.

Therefore,

A priori knowledge is inadequate for gaining knowledge of God. If we cannot define God, then we cannot use Anselm’s first premise.

Therefore, ontological arguments fail.

*Aquinas argues that proof of God’s existence must come from inductive arguments based on a posteriori knowledge.

Descartes (1596-1650):

Perfection is a defining feature of God

“since we do conceive a supremely perfect being we must conclude that a supremely perfect being exists”

Innate ideas:

Descartes argued that there were some ideas that we cannot doubt because we are born with them (innate) - these include ideas about number and shape

One of these innate ideas was the understanding that: ‘God is a supremely perfect being’

Descartes Ontological argument:

  1. I have the innate idea of God as a supremely perfect being - a priori knowledge

  2. A supremely perfect being has every attribute perfectly

  3. Existence is an attribute

  4. A supremely perfect being must possess the attribute of existence

Conclusion: Therefore, God must exist (In the most perfect way)

Descartes’ analogies:

Triangle and Mountain

Kant:

Existence is not a defining attribute (predicate) of any being.

Predicate = characteristics/essential attributes of something (they form part of the definition).

Kant gave his own example/analogy of ‘100 thalers’ (value of coin used in Europe in 18th century)

I can describe the size, shape, weight, material of the coin BUT nothing is ‘added’ to the description if we also say ‘Thalers exist’

Existence identifies that something has been ‘actualised’ (there is at least one example of the thing in the real world). Existence can only be known a posteriori.

Descartes argues God has a predicate of existence as it would be an imperfection to lack this predicate. Kant says existence is not a predicate.

Kant also objects using Descartes own analogies:

We can accept the definition of triangles and mountains BUT we don’t have to accept the existence of either, we could reject the existence and concept of both entirely.

Kants objection:

  • ontological arguments focus on the idea that existence is an essential characteristic of God

  • This is not logically sound because existence is not a predicate and so cannot be used as an essential characteristic of any being

  • Therefore, existence cannot be an essential characteristic of God.

  • So ontological arguments cannot be used to demonstrate that God exists

Response to Kant:

  • Is “necessary existence” a predicate?

  • “If God exists then he exists necessarily” - Kant has not disproven God, just says can’t prove God’s existence a priori.

Malcolms’ development of Descartes:

If God doesn’t exist, he also couldn’t come into existence as he would not then be God - so if he doesn’t exist then his existence is impossible

The logical impossibility of non-existence (necessary existence) is a perfection

Necessary IS a predicate - maybe contingent existence isn’t as Kant claims

If God does exist, then he cannot cease to exist as he wound not then be God - his existence is necessary

  1. God’s existence is either necessary or it is impossible

  2. God’s existence is NOT impossible as it is not self-contradictory

  3. Therefore, God’s existence must be necessary

^^ argument uses modal logic

Modal logic - expressing statements about necessity or possibility

Considers all possible modes of existence

Plantinga:

Using Modal logic

  1. There is a possible world with a being with maximal greatness - a being that exists in all possible worlds

  2. This being has maximal excellence which means it is omnipotent, omniscient and omnipresence

  3. Our world is a possible world

  4. Therefore, this being exists in our world which is God.

Malcolm considers 3 different possibilities regarding God’s existence:

1) God-s existence could be impossible - there is no God

2) God’s existence could be possible - there could be God or there may not be

3) God’s existence is necessary - there must be a God

BUT God’s existence is not contradictory or absurd and therefore is not impossible.

Malcolm argue that any contingent being can be bought into or out of existence by some cause or blind chance so is limited

BUT God's existence isn’t ‘possible’ as that would mean that His existence relies on something else and is contingent which contradicts the definition of God

In having logically eliminated the other considerations regarding the nature of God’s existence, only one option remains.

Therefore, God has necessary existence - the non-existence of God is impossible.

Criticisms of ontological arguments:

1) Rely on agreed definitions of God - many argue we do not have enough knowledge to define God - Aquinas argued God’s existence can only be proven through A posteriori evidence

2) Claims that existence is a part of the essence of God Existence is NOT a predicate - it is not in the essence of God - it is not a defining attribute

3) Uses logical tricks - Guanilo’s ‘perfect island’ response proves Anselm’s logic wrong - Davies says they use circular logic which cannot be trusted

Hick:

  • Modal argument fail as they confuse two types of necessity

  • Hick distinguishes logical necessity and ontological necessity

  • We can accept that it is not LOGICALLY impossible for God to exist (not a self-contradiction) but it is a jump in logic to say that God is ONTOLOGICALLY necessary (actually has to exist in reality)

  • fallacy of equivocation - using a word in 2 different ways without acknowledging the move

  • That there is a God who is ontologically necessary cannot be deductively proven and is instead a ‘hypothesis’