The Ontological Argument
AGO: To clarify the notions of proof in this argument and to examine some definitions of it.
“There exists, therefore, beyond doubt something than which a greater cannot be imagined both in the
understanding and in reality” - Anselm, Proslogion 2, 1077-8
● This argument is different to the types of arguments you have looked at previously so far
● Ontological means “concerned with being”
● It is analytic, a priori and deductive
● Key proponents are Anselm, Descartes and Alvin Plantinga
Deductive -
A conclusion follows necessarily from the premises - there is only one possible conclusion (either
100% true or 100% false)
Analytic -
True by definition - tautologies e.g. the evening sunset > by definition it is the evening
A priori -
Knowledge that is not based on experience
The Queen lives in England
London is in England
Therefore, the Queen lives in England
Deductive arguments can be limited as it is often difficult to establish the premises in the first place,
and the conclusions reached are often obvious from the premises.
GOD - A transcendent, supreme being that is believed to have caused everything in existence and a
source of moral authority
Attributes -
● Eternal
● Omnipotent
● Omnipresent
● Omnibenevolent
● Omnipresent
Anselm 1st Form
Premise 1: God is “that which nothing greater can be conceived”
Premise 2: If God exists only as an idea, then a greater being could be imagined to exist both in the
mind and in reality
Premise 3: This being would exist not only as an idea of the mind
Premise 4: Thus God cannot exist only as an idea in the mind
Conclusion: Therefore, God exists both as an idea and in reality
If someone does something i.e. God is the greatest thing you can think of, he must exist because if he
only exists in your mind, he cannot be the most powerful as he has no influence on the real world.
Therefore, if God is the greatest possible being, then he must exist in both mind and reality.
Anselm’s 2nd Form
, Premise 1: God is the greatest possible (nothing greater can be conceived
Premise 2: It is greater to be a necessary being than a contingent being (can cease to exist)
Premise 3: If God exists only as a contingent being, he can therefore be thought not to exist. Then a
greater being could be thought of that can never be conceived of as non-existent
Premise 4: This being would then be greater than God
Conclusion: God is therefore a necessary being and must exist in reality.
Ontological argument differs from the cosmological and teleological argument as it is a priori instead
of a posteriori and is deductive as well as analytical
Reductio ad absurdum -
Criticisms of the Ontological Argument -
Gaunilo was a contemporary of Anselm, he was a monk who rejected Anselm’s on ‘On Behalf’ of the
fool using three arguments…
1) On Gossip - the fool could have all kinds of made-up things in his, gossip for instance in
unreliable - how should he be able to discern what is true and what is not?
2) You can’t define things into existence
3) The Perfect Island
Anselm’s argument fails because the same kind of logic would force you to conclude that things exist
which certainly do not.
Gaunilo’s argument -
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, we can conceive of an even greater island, that is
one that does exist.
4. Therefore, the Perfect Island must indeed exist in reality.
5. Therefore, the Perfect Island exists
Anselm’s Argument -
1. God is that being than which no greater can be conceived.
2. It is greater to exist in reality than merely as an idea
3. If God does not exist, we can conceive of an even greater being, that is one that does
exist
4. Therefore, God must exist in reality
5. Therefore, he exists
The problem? - The perfect island does not exist, even though the logical argument claims that it
does. The idea of a perfect island is also subjective as everyone pictures something different.
Anselm’s reply -
● Firstly, you cannot, no matter how great the island, compare an island (or anything else) with
the concept of a God.
AGO: To clarify the notions of proof in this argument and to examine some definitions of it.
“There exists, therefore, beyond doubt something than which a greater cannot be imagined both in the
understanding and in reality” - Anselm, Proslogion 2, 1077-8
● This argument is different to the types of arguments you have looked at previously so far
● Ontological means “concerned with being”
● It is analytic, a priori and deductive
● Key proponents are Anselm, Descartes and Alvin Plantinga
Deductive -
A conclusion follows necessarily from the premises - there is only one possible conclusion (either
100% true or 100% false)
Analytic -
True by definition - tautologies e.g. the evening sunset > by definition it is the evening
A priori -
Knowledge that is not based on experience
The Queen lives in England
London is in England
Therefore, the Queen lives in England
Deductive arguments can be limited as it is often difficult to establish the premises in the first place,
and the conclusions reached are often obvious from the premises.
GOD - A transcendent, supreme being that is believed to have caused everything in existence and a
source of moral authority
Attributes -
● Eternal
● Omnipotent
● Omnipresent
● Omnibenevolent
● Omnipresent
Anselm 1st Form
Premise 1: God is “that which nothing greater can be conceived”
Premise 2: If God exists only as an idea, then a greater being could be imagined to exist both in the
mind and in reality
Premise 3: This being would exist not only as an idea of the mind
Premise 4: Thus God cannot exist only as an idea in the mind
Conclusion: Therefore, God exists both as an idea and in reality
If someone does something i.e. God is the greatest thing you can think of, he must exist because if he
only exists in your mind, he cannot be the most powerful as he has no influence on the real world.
Therefore, if God is the greatest possible being, then he must exist in both mind and reality.
Anselm’s 2nd Form
, Premise 1: God is the greatest possible (nothing greater can be conceived
Premise 2: It is greater to be a necessary being than a contingent being (can cease to exist)
Premise 3: If God exists only as a contingent being, he can therefore be thought not to exist. Then a
greater being could be thought of that can never be conceived of as non-existent
Premise 4: This being would then be greater than God
Conclusion: God is therefore a necessary being and must exist in reality.
Ontological argument differs from the cosmological and teleological argument as it is a priori instead
of a posteriori and is deductive as well as analytical
Reductio ad absurdum -
Criticisms of the Ontological Argument -
Gaunilo was a contemporary of Anselm, he was a monk who rejected Anselm’s on ‘On Behalf’ of the
fool using three arguments…
1) On Gossip - the fool could have all kinds of made-up things in his, gossip for instance in
unreliable - how should he be able to discern what is true and what is not?
2) You can’t define things into existence
3) The Perfect Island
Anselm’s argument fails because the same kind of logic would force you to conclude that things exist
which certainly do not.
Gaunilo’s argument -
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, we can conceive of an even greater island, that is
one that does exist.
4. Therefore, the Perfect Island must indeed exist in reality.
5. Therefore, the Perfect Island exists
Anselm’s Argument -
1. God is that being than which no greater can be conceived.
2. It is greater to exist in reality than merely as an idea
3. If God does not exist, we can conceive of an even greater being, that is one that does
exist
4. Therefore, God must exist in reality
5. Therefore, he exists
The problem? - The perfect island does not exist, even though the logical argument claims that it
does. The idea of a perfect island is also subjective as everyone pictures something different.
Anselm’s reply -
● Firstly, you cannot, no matter how great the island, compare an island (or anything else) with
the concept of a God.
