he will debate anything for hours regardless of how passionate he is about it, but the one interest that he developed at school and clung to over the years was anything about the borgias (the family, not the tv show). he's also pretty generally interested in the various christian schisms and all the catholic infighting that happened around that period of time. he has a fairly robust understanding of catholic history and sometimes gets pretty incensed when he's debating that kind of stuff, which often surprises people, because he's generally viewed as being not super 'worldly' or historically minded.