Descartes on God

The Existence of God

- In order to answer that question, Descartes interrogates the idea of God:

Descartes' Argument

- Sth. cannot arise from nothing: for example, heat can only be caused by sth. hot;?the idea of heart can only be caused by sth. hot, even though the idea itself is not hot. There needs to be a cause.

- The cause must always be greater or equal to the effect.

- Ideas can be caused by other ideas or by real things, but either way there cannot be an infinite regress; there msut be an existing first cause.

- If I have an idea so great that is cannot have been caused by me, it must have been caused by sth. external to me.

- I have the idea of God, an infinite, supremely intelligent and powerful being.

- Unlike other ideas, theses attributes could not have originated in me alone. Therefore, God must necessarily exist.

Multiple arguments?

- There can't be an infinite regress; there must be a first cause.

- The idea of God could not have originated in me alone; it must come from sth. external to me.

- My sense of my own imperfection and limitation only makes sense with reference to an idea of perfection, which must have been caused by th. perfect.

Dependent Existence

- Could I exist if God did not exist?

- If I were the cause of my own existence, I would be the cause of my idea of perfection, so I would have to be perfect myself, i.e. I would be God.

- I would also possess the power of self-creation, but I have no experience of this; on the contrary, I am aware of my limited power. Therefore, I am dependent on sth. else.

- If caused by sth. else, that cause must be:

????i) at least as real as me

????ii) be a thinking thing

????iii) be perfect or contain the idea of perfection

????That cause must be God, or itself caused by God.

Is the idea of God an innate idea?

- My idea of God

????i) does not come via the senses

????ii) is not created by me, so it must be an innate idea, implanted in me by God

????If this idea of a perfect being is in me, then God must exist. It is, ...

Ontological Arguments

- Descartes also offers a fairly traditional ontological argument for the existence of God:

- Existence is part of God's essence. If God did not exist, he would lack a perfection; but he is perfect, therefore he must exist.

- The idea of God and God's existence are inseparable: "I am not free to think of God without existence".

- There cannot be more than one necessarily existing God, for another of this perfections is being unlimited.

An Ontological Argument

God as Guarantor of Truth

- God necessarily exists [and just proven] and, as a perfect being, He would not deceive us, deception being an imperfection.

- Nor would He give me an unreliable faculty of judgement, even if, due to being imperfect myself, I might sometimes make mistakes. (I might occasinally get things wrong, but I'm not going to be consistently mistaken.)

- Descartes suggests that the existence of God removes the possibility that he might be being deceived about mathematical and other intellectual truths, but he continues to suspend judgement regarding the reliability of the senses.

Summary

- Descartes offers us not one but multiple arguments for the existence of God:

????- Causal Argument: not hing (not even an idea), can come from nothing.

????- Dependence Argument: my existence depends on the esistence of sth. greater than me.

????- Innateness Argument: I could not have perceived or created the idea of God; he must have created it.

????- Imperfection Argument: my experience of my own imperfection presupposes the idea of perfection, which must have come from sth. external to me.

????- Ontological Argument: Existence is part of the essense of God, conceived as a perfect being.

- All these arguments, which are closely inter-related, rely on

????i) the idea of God as a perfect being,

????ii) the fact of my own existence as a thinking thing (proved by the cogito)

- He now knows that,

????i) he exists,

????ii) God exists,

????iii) he's not being consistently deceived

Questions

- What does Descartes mean when he says that there must be at least as much reality in a cause as in its effect?

- What reasons does Descartes give for the claim that the idea of God could not have originated within us?

- Why does Descartes think that I cannot be the cause of my own existence?

- Is non-existence an imperfection?

- Does Descartes convincinly prove the existence of God?