different stories, he is suggesting there is a case to be made that there should be rational optimism about the state of human condition we will talk to you about that. here are the phone numbers on the screen. let s take a look at his theory and we will come back and talk to you. here are a few examples of how things are getting better. life expectancy. in my lifetime, up roughly one- third, doubled in 200 years. we are adding this is globally. this is not the u.s. or anything like this but the world. adding life expectancy at the rate of about five hours a day. host: nat ridley is a writer for the economist. he is british, as you can hear from his accent. science editor, washington correspondent for the economist and has a regular column in the daily telegraph. also was the chairman of a british bank that has some in society criticizing him, chairman of northern rock that needed a bailout. but let me give you the pros and cons. first of all, gail collins is lookin