How does Descartes prove the existence of God? Use these notes when answering the question in a detailed, concise, and excellent manner: Descartes proves God’s existence by using the principle of causation.
Descartes’ mind is made up of ideas and modes of thinking. 
Ideas are what we think about
When we do not refer our ideas to anything outside of us, we can know that the idea exists.
When we have ideas, we cannot deny that they exist.
Anything that exists is an effect.
According to the principle of causation, any effect implies a cause and any cause is as real as its effect.
Therefore, any time we have an idea, we know that the idea has been caused and the cause of this idea must be at least as real as its effect.
So, if we have an idea for which we know we are not the cause, then we know something else exists that must have caused it and is at least as real as it.
We have the idea of God, which by definition is infinitely powerful and infinitely knowledgable
If we were the cause of God, we would be infinitely powerful and infinitely knowledgable. 
If we were the cause of God, in other words, we would be God
We are not God
Therefore, we cannot have been the cause of our idea of God
But we cannot deny that the idea of God exists, so it must have been caused by God
Therefore, God exists.
