I really, really like this formulation - because you're absolutely right in that thing thing left out is the fact that once you've read/internalized an idea, no matter where it comes from, it's part of your internal thought framework.

And, yeah, Foucault was very much part of what I was trying to think through above, because we so rarely seem to question the idea that he can go wherever we want him to - unless we're questioning theory as a whole, that is. And that don't seem right :)