Since 1980, the temperature of the planet has risen by 0.8 degrees Celsius, resulting in unprecedented melting of the Greenland ice sheet and the acidification of oceans. In 2015, 175 million more people were exposed to heat waves compared with the average for 1986 to 2008, and the number of weather-related disasters from 2007 to 2016 was up by 46 percent compared with the average from 1990 to 1999. This is nothing in comparison to the horrors that await us as temperatures continue to rise. According to recent projections, global temperatures are set to increase by 3.2 degrees by the end of century. This will lock in sea level rises that will mean that the cities, towns, and villages currently occupied by 175 million people—including Hong Kong and Miami—will eventually be underwater.
There is overwhelming scientific evidence that warming is largely caused by the actions of human beings. Surveys of the scientific literature have consistently found that over 90 percent of scientists believe that climate change is real and manmade, with most surveys asserting a consensus of 97 percent. And yet there is in the public mind a perception that the reality of man-made climate change is uncertain. This is in large part caused by a sustained lobbying effort from the fossil fuel industry aimed at spreading seeds of doubt. But it may also result from a failure to appreciate how uncertain most of human knowledge is. Many believe that science provides “proven facts,” and against this assumption any degree of uncertainty can seem to render a hypothesis “unscientific,” a matter of speculation rather than demonstrable knowledge.
Philosophy can help with this. The 18th-century philosopher David Hume was one of the great sceptics of philosophy. He argued there was no way of demonstrating that our conscious experience corresponds to anything real; that a conscious experience of a table, for example, corresponds to a real physical table out there in the external world. But Hume didn’t think skepticism was something to be feared. You merely had to stop philosophizing and get on with life and skeptical worries about the external world evaporate like morning mist.
In that case, what’s the point of entertaining such possibilities? One benefit of skeptical reflection, according to Hume, is it can lead to a healthier relationship with evidence. Most people are apt to have dogmatic opinions, he wrote. To temper or balance their beliefs undermines their passions and makes them uneasy, and so they remain obstinate. “But could such dogmatical reasoners become sensible of the strange infirmities of human understanding, even in its most perfect state,” Hume wrote, “such a reflection would naturally inspire them with more modesty and reserve, and diminish their fond opinion of themselves, and their prejudice against antagonists.”
I am struck by how Hume’s eloquent description of dogmatic tendencies rings true today. We are living in an increasingly polarized age in which people run away from uncertainty by bolstering their convictions to the point where no alternative is given the slightest credibility. But, as Hume points out, this kind of obstinacy is simply incompatible with the realization that even our most basic beliefs, such as the belief that that there is an external world or that the universe has existed for more than five minutes, are not known with 100 percent certainty. One of the many values of a philosophical education is that it teaches the importance of doubt. [Continue reading…]