nitpicking here, but Cogito Ergo Sum (“I think, therefore I am”) has absolutely nothing to do with intelligence. in modern vernacular you might translate it as "i percieve/witness therefore i exist"
You might take it that way, but are you sure that's correct. The derivation/etymology of cogito appears to imply active thought, as does penser (I've always assumed Descartes conceived it in French, and translated, but I confess I don't know which natural language - if any - his mind was using). As opposed to merely passively regarding the World. The epigram's context is "application of reason", at least.
I'm pretty sure when Decartes said that, he meant that that's the only thing we know for sure to be true, since everything else could be a hallucination. He wasn't making an argument for cognitive enhancement... was he?