Astronomers once believed the sun revolved around the earth. In the 19th century, scientists thought the shape of a person’s skull could reveal their mental strengths or weaknesses. And in the 20th century, many scientists strongly opposed the idea that continents were drifting. All views have now been completely overturned.
So can we trust the scientific truths of today? Is it possible to identify scientific ideas and claims that endure forever and are not susceptible to future scientific revolutions? Some would say certainly not. But my new book Identify future-proof sciencecombines historical, philosophical, and sociological investigations to argue that this is often possible.
An exercise in humility
There is a philosophical attitude, sometimes referred to as intellectual humility, that involves questioning whether there are ultimate truths by looking at evidence from scientific revolutions and paradigm shifts (changes in belief and knowledge systems) throughout history.
At first glance, that seems very reasonable, maybe even rational. One might add that humility is a virtue. Who would dare say that some scientific claims that are endorsed today will still be supported by scientific communities 5,000 years from now?
Those who are skeptical of scientific claims often use a simple argument: Scientists have been certain in the past and ended up being wrong. The physicist Albert Michelson (of Michelson-Morley fame) wrote in 1903: “The more important fundamental laws and facts of science have all been discovered, and these are so firmly established that there is a possibility that new ones will ever supersede them Discoveries is extremely far away.”
This was just before physics was dramatically changed by the development of general relativity and quantum mechanics. There are many other quotes of this type that seem to demonstrate the overconfidence of even the best scientists.
Naomi Oreskes, historian and defender of science, wrote in her 2019 book Why trust science? that “the history of science shows that scientific truths are ephemeral” and “the contributions of science cannot be regarded as permanent”.
Physics Nobel Laureate Steven Weinberg said: “There are truths out there to be discovered, truths which, once discovered, will form an enduring part of human knowledge.”
But Oreskes’ answer is clear: “Weinberg is a brilliant man… But this comment reflects either a shocking ignorance of the history of science or a shocking disregard for evidence gathered from another field.”
She means history.
Scientific Facts vs. Historical Truth
What then are “scientific facts”? In accordance with intellectual humility, “facts” exist only in a weak sense: they are fleeting and relative to the current paradigm. With paradigm shifts throughout history, “facts” have often been left behind and replaced with new ones.
People who are committed to intellectual humility don’t necessarily say that nothing lasts. They say we don’t know which claims (if any) are immune to future paradigm shifts. Nor are they saying that we shouldn’t trust science; Oreskes is absolutely clear.
But intellectual humility begins to seem absurd as soon as it is driven to its logical conclusion. It would mean we don’t really know that the sun is a star, that continents are drifting, that smoking causes cancer, or that the current global warming is real and man-made.
In all of these cases (and many more) the opinion of the scientific community has long since set the matter above reproach. It’s absurd to think that 50 years from now, after a scientific revolution, we could look back and say, “Smoking used to be thought to cause cancer.”
If that were reasonable, one might also assume that the earth could be flat. The view slides into “radical skepticism” where one assumes that we could all be living in a dream or in a dream The Truman Show.
But what if I only think like this because I’m a cognitive prisoner, trapped in the conceptual scheme of the paradigm I grew up in? Sure, to me it seems totally indisputable that the sun is a star, and it seems absurd to doubt it. But maybe it won’t seem so absurd to those living in a future paradigm.
Observing the previously unobservable
A lot can be learned from history. For example, consider the history of continental drift. It used to be just speculation that continents move. Then, in the 20th century, it became a solid theory and finally “scientific fact” that became the consensus view among scientists.
At this point the skeptic might think that the solid scientific consensus proves nothing as the consensus might have evolved for bad reasons like “groupthink”. But look what happened next: we developed instruments that could observe continental drift in real time. Thus, continental drift is clearly future-proof: we can see it taking place.
Such developments are crucial to show that solid scientific consensus can be linked to truth. As my book shows, when really solid scientific consensus is followed by the development of instruments that can see and see the thing or process in question, the scientific consensus has been confirmed.
There are many examples. We now have microscopes that can show the behavior of viruses, and we see viruses doing what we already knew them to do.
We can also use microscopes to see the structures of all sorts of molecules, and once again where there was a solid scientific consensus about the structure (e.g. the hexagonal benzene ring molecule) we found that the consensus was right. This is also the case when it comes to the double helix structure of DNA.
These cases show that a solid international scientific consensus can be trusted to reveal the truth. And that includes the cases where we have not yet (and perhaps never will) develop technologies that allow us to observe what is currently unobservable.
What about the concern that scientific communities have historically reached a strong consensus on an idea that has now been thoroughly rejected?
I have found that throughout the history of science, when the following two specific criteria were met, the claim in question was never overturned, but instead simply further confirmed:
1. At least 95 percent of the relevant scientists are willing to formulate the claim unequivocally and without reservations or safeguards. If asked to do so, they would be willing to call it “established scientific fact.”
2. The relevant scientific community is large and international, encompassing a significant diversity of perspectives (such as in climate science).
These criteria are met only when there is a large body of first-order scientific evidence supporting the claim in question. You are the best proxy we can ever have for the impossible alternative, which is to analyze all the scientific evidence yourself, over many decades, from a multitude of different perspectives. In practice, these two simple rules can help us identify future-proof science.
This article was originally published on The conversation through Peter Vickers at Durham University. Read the original article here.