P30: An actual intellect, whether finite or infinite, must comprehend God/Nature’s attributes and God/Nature’s affections, and nothing else.

Dem.: A true idea must agree with its object (by A6), i.e. (as is known through itself), what is contained objectively in the intellect must necessarily be in nature. But in nature (by P14 C1) there is only one substance, viz. God/Nature, and there are no affections other than those that are in God/Nature (by P15) and which can neither be nor be conceived without God/Nature (by P15). Therefore, an actual intellect, whether finite or infinite, must comprehend God/Nature’s attributes and God/Nature’s affections, and nothing else, q.e.d.