Serum and virus. Percentage of salted horses. Rinderpest. Dictates of common sense.
In the long run, physicists are, no doubt, getting closer and closer to the truth. But you can never be sure when the long run has arrived. And in the short run—to adapt Keynes’s proverb—we are often all wrong.
It is perhaps the biases of science reporting in the popular press that produce the most misinformation, especially in medicine. (…) When a drug is tested on animals and seems promising, it makes headlines, even though the majority of drugs that pass animal trials never become usable for people. And barely a day goes by without the media exploiting an almost universal misunderstanding of statistics and reporting something that has no relevance to anything. When researchers are said to have found that an effect occurs to a statistically significant degree, this means that it probably isn’t caused by a fluke, not that it is large or definite enough to be useful.
A school of ancient philosophers, the followers of Pyrrho of Elis (who died C270BC), came up with a consistent but impractical response to the problem of whom to believe when expert sources disagree or are found to be unreliable. Believe nobody, they said: suspend judgment on everything. Scholars have debated whether anyone could have lived a life according to this principle, and the consensus is no, they could not. Suspending judgment may keep you free from erroneous beliefs, but it also makes it impossible to decide rationally on what to do about anything.
