Ever since the age of enlightenment science has replaced religion as the conveyor of truth. But science, just like any human endeavour, is not infallible. Scientists are often subject to the same pressures and personal biases of the population at large. The limits of scientific knowledge can perhaps be best captured in this little anecdote (told by Carlos Moedas at the European Research Council in 2017):
Imagine a man about to sit down and eat a meal in his kitchen, when a time-travelling scientist from the future suddenly appears. The scientist warns the man that to avoid eggs, as they are high in cholesterol and could significantly increase the risk of a heart attack. Happy with the thought that he has saved the hungry man from future health problems, he is quickly on his way. Then the scientist appears again saying he was wrong, and that actually there are two types of cholesterol, one bad, one good. So, he advises the man to only eat the egg whites, but not the yolks. So, he leaves a second time. But he is back again straight away. This time he tells the hungry man that they are now unsure in the future about how cholesterol in food effects cholesterol in the body. And that the eggs are probably fine to eat!
This amusing anecdote illustrates the difficulty of establishing social and economic policy based on evolving scientific facts and discoveries. The egg example might seem trivial, but it is not, the global egg industry is worth $160 Billion dollars and employees hundreds of thousands of people, scientific advice on the suitability of egg consumption has a material impact on the quality of life of many people, many of whom are based in poor countries. Today, scientists inform us that Climate Change is an urgent problem that requires us to fundamentally re-shape our economy. But scientists disagree as to the severity of climate change, while some report Climate Change is hitting harder and faster, others argue that we have no climate emergency. These conflicting positions complicate public policy, and especially so, when both the cost of acting and not acting, is potentially severe.
In the face of evolving and conflicting scientific conclusions, many people and many politicians find themselves forced to make a choice on subject matter they hardly understand. In doing so, our choices become an act of faith rather than an act of reason. And when science gains the quality of religious dogma, truth loses all relevance.