Medieval Reasoning

Philosophy, Scuola Normale Superiore, Pisa Uncertain Reasoning “The boy who cried wolf” is one of Aesop’s more famous fables. In the story, the boy plays a prank on the villagers by shouting that a wolf is chasing the sheep is supposed to be watching. The villagers run up the hill to help the boy chase the wolf away and protect the sheep. They are annoyed to discover they have been tricked and this amuses the boy greatly. The boy decides to repeat the trick and again, the villagers react, but they are beginning to learn that the boy can’t be trusted. So when a wolf does in fact start harrassing the sheep, the boy’s cries go unanswered and his flock of sheep are scattered across the hillside. In recent months, I’ve seen a few instances of news stories that reminded me of this fable. For example, I read about some people refusing to evacuate from hurricane-prone areas, the reason they gave being that “the scientists had been wrong before” I suppose the person making this claim thinks they are acting like the villagers in the story of the boy who cried wolf. In a sense, this is a perfectly understandable instance of confirmation bias: the successes of science are so commonplace, so ubiquitous that they pass un-noticed, whereas the few times science gets things wrong receive a lot of attention. But the person refusing to evacuate is not like the villagers in this fable. The boy is not playing a prank on the villagers, he is earnestly and carefully trying to give them the best information possible about the wolf. He isn’t gleefully tricking the villagers by shouting “wolf” he is saying “there might be a wolf and it might be best to run up the hill to make sure he doesn’t get the sheep”. And when the boy’s cries aren’t heeded, the wolf doesn’t just scatter the flock of sheep, but it destroys the whole village. Even if most of the time it’s a false alarm, it’s probably best to take precautions. This seems like a smaller-scale version of something one often hears in discussions of climate change: that the science is uncertain. Well, there are uncertainties in many of the details of climate modelling and projection, but none that seriously threaten to undermine confidence that the Earth is warming at an unprecedented rate. But even if there were reasons to be more uncertain in the probability of catastrophic future warming, wouldn’t a level of precaution be advisable? Uncertainty is no reason not to take more action than we currently do on pre