[Marco opens his mouth, though he's speechless for a moment longer. That's not the question he was expecting to hear, and... well, it calls into question what Dr. Osborn has experienced himself.

One thing at a time, though. As difficult as it is for him to talk about this, he knows he can't pry too quickly.]

... Well, fundamentally, I'm not sure if there's a difference between the two. [His expression is wry, but calling it a smile would be pushing it.] No matter how convincing the... the voices may be, they're still my own creation.

[That's important for him to remember, actually. The people he thinks he hears... They're not really there. It's ALL him.]