Whatever I clearly and distinctly perceive to be contained in the idea of something is true of that thing.
I clearly and distinctly perceive that necessary existence is contained in the idea of God.
Therefore, God exists.
I have an idea of supremely perfect being, i.e. a being having all perfections.
Necessary existence is a perfection.
Therefore, a supremely perfect being exists.
How can I convert it to first-order logic? Furthermore, how can we test for the validity of the rule of inference?
Edit: How sound is the argument?