So, I was reading old Joker things (not so old 1999) and you can notice how that Joker was very different, I have read that old joker before but since I finished the new52 batman I wanted to read pre-n52 again and compering both...nowadays they use a philosophical Joker often and you feel his speaking is more educated, I read N52 suicide squad a while ago and they used that philosophical route. Before...well maybe the killing joke was philosophical in one way but I can't remember how all this began in comics, I think the movie "dark knight" was an influence but you're the expert. What can you remember about this?
By the way I'm not saying I prefer Philosophical-Joker but It's curious...