Passage 1　　“It Nineteenth-century humorist Artemus Ward once warned the readers: ‘It ain’t what you don’t know that hurts you; it’s what you know that just ain’t so. ’”　　(1)There’s good advice in that warning to some of television’s most fussy critics, who are certain that every significant change in American social and political life can be traced, more or less directly, to the extensive influence of TV.　　This is an understandable attitude. For one thing, television is the most visible, ubiquitous de- vice to have entered our lives in the last forty years. (2)It is a medium in almost every American home, it is on in the average household some seven hours a day, and it is accessible by every kind of citizen from the most desperate of the poor to the wealthiest and most powerful among us.　　If so pervasive a medium has come into our society in the last four decades and if our society has changed in drastic ways in that same time, why not assume that TV is the reason why American life looks so different?　　Well, as any philosopher can tell you, one good reason for skepticism is that you can’t make assumptions about causes. They even have an impressive Latin phrase for that fallacy, post hoc, ergo propter hoc. For instance, if I do a rain dance at 5 P.M. and it rains at 6 P. M., did my dance bring down the rains? Probably not. (3) But it’s that kind of thinking, in my view, that characterizes much of the argument about how television influences our values.　　It’s perfectly clear, of course, that TV does influence some kinds of behavior. For example, back in 1954, Disneyland launched a series of episodes on the life of Davy Crockett, the legendary Tennessee frontiersman. A song based on that series swept the hit parade, and by that summer every kid in America was wearing a coonskin cap.　　(4) The same phenomenon has happened whenever a character on a prime-time television show suddenly stimulates a strong response in the country. Countless women tried to capture the Farrah Fawcett look a decade ago when “Charlie’s Angels “first took flight. In the mid-1980s, every singles bar in the land was packed with young men in expensive white sports jackets and T-shirts, trying to emulate the macho looks of “Miami Vice’s” Don Johnson.　　(5) These fashions clearly show television’s ability to influence matters that do not matter very much. Yet, when we turn to genuinely important things, television’s impact becomes a lot less clear.