(Developed by P. Bishop) 12 Angry Men (and in those days, 1957, it was all men!) is an outstanding dramatization of critical thinking. The story is simple: A teen-age boy is accused of murdering his father. The evidence against him seems indisputable, at least to 11 of the 12 men on the jury. The 12th man, however, (Henry Fonda, the hero) wants to “talk about it.” You get the idea. The case revolves around four or five pieces of evidence that seem to support the boy’s guilt. Each of those pieces of evidence, however, as all pieces of evidence, needs to critically analyzed to see whether there are any required assumptions that have plausible alternatives. (As you know from the reading, you can’t disprove an assumption, but you can show that it might not be true by proposing one or more plausible alternatives, alternative assumptions that have some support of their own). I filled in the first piece of evidence in the movie that is subjected to critical examination. There are at least three others and probably more. Find at least three and up to five pieces of evidence that support the boy’s guilt, but that later need to be reconsidered in light of the assumptions required to use the evidence in that fashion. Inference: The boy is guilty. Evidence: The knife found in the father’s chest was a very unusual switchblade knife. A pawn broker testified that he sold the boy a knife just like that earlier that evening. He said it was the only one he had ever seen like it, and the boy’s friends testified that the boy showed them the knife earlier that evening. (Notice that the indisputable evidence was not that the pawn broker sold the boy the murder weapon nor that the boy’s friends saw him with the murder weapon. The only indisputable evidence is that is what each said in court.) STOP READING HERE IF YOU WANT TO BE SURPRISED BY THE MOVIE!!!!
Assumption required to be able to use that evidence: