When I was a young faculty member, my laboratory was deeply engaged in studies of zinc-containing proteins. One evening, after our two sons had been tucked into bed, I was watching The Simpsons and the episode began, uncharacteristically in black and white, with a man trying unsuccessfully to start his car. Another man says, “You said that you wanted to live in a world without zinc…” and explains the essential roles that zinc plays in various machines and expands on the frightening and dysfunctional scenario. I was genuinely concerned that I was hallucinating and wondered whom I could call to confirm what I thought I had seen. We are now living in a world where the reality of facts and the importance of scientific inquiry and responsible journalism are questioned with distressing frequency. This trend needs to be called out and arrested; the consequences of allowing it to continue are potentially quite damaging.
Facts are statements that have a very high probability of being verified whenever appropriate additional observations are made. Thus, facts can be reliably used as key components in interpreting other observations, in making predictions, and in building more complicated arguments. For example, consider the proposition that the law of universal gravitation (LUG) accurately predicts the behavior of matter. The LUG is considered a fact given the vast and different sorts of observations that support it. The power of such accepted facts can be illustrated by the concept that the universe contains a large amount of “dark matter.” Astronomer Vera Rubin obtained evidence that the detailed rotation of galaxies was not consistent with the LUG and other laws of physics, leading to two interpretations: Either the LUG was not correct in this context, or additional, large amounts of mass were present but not observable. Because of the wide support and acceptance of the LUG, the dark matter hypothesis was taken seriously, and additional evidence was interpreted in this context.
Consider the present “post-fact” world in this context. The lack of acceptance and cynical or ignorant questioning of well-documented evidence erode the perception that many propositions are well-supported facts, weakening the foundation on which many discussions and policies rest. Under these circumstances, numerous alternatives appear to be equally plausible because the evidence supporting some of these alternatives has been discounted. This creates a world of ignorance where many possibilities seem equally likely, causing subsequent discussions to proceed without much foundation and with outcomes determined by considerations other than facts.
Overly discounting information from appropriately trained researchers based on well-conducted studies, or from well-qualified journalists who pursue information with good practices that include interactions with multiple independent sources, can falsely restrict the available evidence. If evidence is judged without regard for its methodological basis, as well as a thorough assessment of sources of bias, unreliable conclusions may be drawn. If shoddy evidence is accepted, false interpretations may appear to be plausible even though they lack substantial evidentiary support. If robust evidence is undervalued or ignored, excess uncertainty will remain even when some propositions should be considered well established.
To avoid sliding further into a world without facts, we must articulate and defend the processes of evidence generation, evaluation, and integration. This includes not only clear statements of conclusions, but also clear understanding of the underlying evidence with recognition that some propositions have been well established, whereas others are associated with substantial remaining uncertainty. We should acknowledge and accept responsibility for, but not exaggerate, challenges within the scientific enterprise. At the same time, we should continue to call out statements put forward that are factually incorrect with reference to the most pertinent evidence. Without taking these steps forcefully, we risk living in a world where many things do not work as well as we need them to.