The Ontological Argument
Religious Studies: OCR A Level, topic 1.5.1
A Priori Arguments
Arguments based on reason are valid a priori, without the need to refer to observations from experience.
A priori arguments
- A priori arguments are simply logically true in the same way that the following argument is logically true:
- All men are mortal;
- Socrates is a man;
- Therefore, Socrates is mortal.
A priori = true by definition
- A priori arguments are true by definition - in the same way that 2 & plus;2 = 4 is true by definition as another way of defining 2 + 2 is to call it 4.
- If it can be shown that God exists by definition, then a priori arguments work.
The Ontological Argument
The argument is known in different forms. The generally accepted classical formulation is from Anselm (1033-1109). It is found in chapters 2-4 of his work Proslogion.
Logical deductive argument
- The logical demonstration in the argument either totally succeeds or totally fails – it is a logical deductive argument.
Anselm’s argument (1st form)
- God is that which nothing greater can be conceived (call this ABC).
- Even the atheist can have this definition in his understanding.
- But if he has it in his understanding (ie in the mind) only, then there must be a greater being who exists both in the mind and reality (it is greater to exist both in the mind and reality).
- So, by the definition ABC, God must exist both in the mind and in reality.
Self-contradiction (1st form)
- Another way of saying this is that it is self-contradictory to be capable of conceiving something that nothing greater can be thought, and at the same time to deny that something really exists.
Anselm’s Argument (2nd form)
- The second form of the argument is developed to show the impossibility of conceiving of God as not existing.
- God cannot not be. Any lesser form of existence where it was possible not to be would not fit with the definition of God.
Theory of the 2nd form
- God is ABC (see 1st form).
- It is greater to be a necessary being than a contingent being.
- If God exists only contingently, it would be possible to imagine a greater being who exists necessarily.
- But if God is ABC, then that being has to be God
- So God must be a necessary being and exist in reality.
- It is important to note that this is logical necessity and not factual necessity (the kind of necessity arrived at in the cosmological argument).
Test yourself on The Ontological Argument
What are a priori proved arguments true by?
In which of Anselm's works are the forms of the ontological argument found?
What does the second form of Anselm's ontological argument show?