[Oh. Eureka. Now the pieces are snapping into place.]

Because you need to have an explanation that isn't hallucinations, because the hallucinations themselves will be indicative of something else. And that's what you're really afraid of. It's not about needing a physical method of therapy over a spiritual one. It's that you need what's being treated to be something other than what you're afraid it is.

[She's not going to ask the next logical question that follows from that. She's curious, not cruel, and he's resisting this something fierce already. But that doesn't mean she doesn't have her guesses.]