I will cast my vote for anaesthesia. While this invention may not have changed the world for all, it has certainly altered the lives of many for the good. Imagine a world without anaesthesia. It makes me shudder.
Howard Gardner and I are probably one of the few couples who replied to your request. Last night we were at a party and we mentioned this project. I said that Howard's and my choices (Western classical music, Howard; vs. anaesthesia, Ellen) showed how different we were, Howard the optimist, I the one who thinks of the grim side of life. At the party was Yo Yo Ma, who listened with interest and said, without skipping a beat, that our two choices were not so different, because "One is a form of the other." (Interpret that as you will “ I take it to mean that music is the ultimate escape from pain, but also perhaps that anaesthesia [when needed] is as pleasurable as music).