Merrin looks at the circlet in her hands, and...hesitates, because this is still pretty scary actually. 

Is Merrin hesitating because of the actual dangers of cognitive enhancement, or for some weird Merrin reason? Probably some weird Merrin reason. (His judgment is that Merrin, who has spent most of her life trying to track thoughts just a little too big for her, will in fact feel more rather than less like herself at this level of enhancement.)

"You aren't the only person to receive one of these," he says. "Most of Civilization's top researchers are in fact receiving a version several times more powerful, which requires special Keeper training to even put on safely.

"... in general, Civilization tries not to place people where their ability to do their jobs would benefit too much from this kind of enhancement," he continues, "not that it was a possibility until recently. It's true that normally, if we need a smarter person to do a job, we simply hire a smarter person. You, however, were chosen for qualities much rarer than the requisite level of general intelligence to be an Exception Handling medtech, and yet it remains true that you would do better in your current role if those requisites were met rather than not met.

"You do not have to. You have been doing quite adequately" really better than adequately, but Merrin "without it. It is, however, our judgment that both you and Civilization would benefit from you wearing it."