I am currently studying some aspects of Spinoza's philosophy, mainly in contrast to Kant. It seems to me that Spinoza is just the kind of "dogmatic metaphysician" Kant criticises. I know that Kant tried to "proof" God's existence in his pre-critical phase, but later changed his mind (I refrain from going into details). I therefore wanted to have a look at Spinoza's "proofs". The first one says:
In the first place, a priori thus: 1. Whatever we clearly and distinctly know to belong to the nature of a thing, we can also truly affirm of that thing. Now we can know clearly and distinctly that existence belongs to the nature of God; Therefore...
It seems to me that this is far from "a priori" as Kant defines it. Furthermore, it rather seems to be a tautology. Because to say that we know that God exists because we clearly and distinctly know what his nature is means the same thing as to already know that he does exist.
Are there any other ways to read this? Am I mistaken? I am not looking for affirmation but on the contrary for arguments against my maybe premature opinion.