[He sits opposite her, glancing over her notes.]

He may not wish to be happy, but happiness is just as much a necessity to a person's wellbeing as eating or sleeping. We all instinctively seek it out, through one means or another... I doubt he would have agreed to your idea, if that weren't true.

[In fact, he would probably have just avoided Athena altogether. The fact he puts up with her is telling.]