Reasons to trust science

Twice a month, The duty challenges enthusiasts of philosophy and the history of ideas to decipher a topical question based on the theses of an outstanding thinker.

The recent election campaign was the occasion for an unprecedented mobilization of those who oppose health measures and vaccines against COVID-19. Protesters heckled near schools and hospitals, threats and hate messages circulated on social networks and some even threw projectiles at the Prime Minister of Canada. Admittedly, a good number of citizens resistant to vaccines express themselves within the democratic framework and in respect of the law. The rejection, however, comes against the backdrop of a more general distrust of modern science, scientists and their conclusions.

In his work Why Trust Science ? published in 2019, historian Naomi Oreskes specifies the circumstances under which science and scientists can be trusted. Harvard University professor and columnist at the magazine Scientific American asks the question: “If scientists are wrong sometimes – and of course they do – how can we know they are right now? […] How to assess the truth of scientific assertions when we know that they can one day be contradicted? “

Because science and scientists can be wrong. Prescribed around 1960 to relieve nausea due to pregnancy, thalidomide has caused more than 10,000 serious birth defects. In 1986, the space shuttle Challenger was diving in the sea a few minutes after its launch. And just before the COVID-19 outbreak, a study conducted among others by Johns Hopkins University concluded that pandemic preparedness was nowhere very good, but that the United States and the United Kingdom were the two countries where it was the best, New Zealand being at 35e rang.

Ignore science

Far more often, however, ignoring science leads to disaster. In the early 1950s, several experts warned the British government of the dangers of smog. The authorities did not heed these warnings and the acute episode of 1952 left between 10,000 and 12,000 dead in London. Diseases like measles are making a comeback where vaccines are refused. Questioning the medical consensus on the viral origin of AIDS, South African President Thabo Mbeki refused for several years offers of effective drugs and treatments, which probably caused more than 300,000 deaths in his country. Closer to home, the United States and Brazil, the two countries most bereaved by COVID-19, have had the misfortune of having heads of state resolutely hostile to science.

Oreskes notes that from the middle of the XIXe century, it was believed that the reliability of science came from its method. To the extent that the scientific method was scrupulously followed, valid results would be obtained. But what is this method? Oreskes retraces various attempts to circumscribe it, through the positivism of Auguste Comte, the Verification program of the Vienna Circle and the refutability of Karl Popper. To each of these attempts, however, serious objections can be raised. Today, and without subscribing to the theoretical anarchism of a Paul Feyerabend, we have given up on the idea of ​​methodological prescriptions which would apply universally and would give assured results.

Commitment of scientists

What then to turn to? Oreskes argues that “the adequate foundation of public confidence in science is the sustained commitment of scientists to the natural world, coupled with the social character of science which includes procedures for the critical analysis of claims.”

It is important to underline that science is based first of all on an empirical approach, on a continual confrontation of scientists with the natural world. The most elegant speculations have frequently fallen under the ax of a few stubborn observations.

But science is not simply the work of an amalgamation of isolated researchers, however brilliant they may be. It is based on a community, on a group of experts and specialists. You don’t have to be an expert to understand that stars who offer miracle cures or fundamentalists who reject evolution are not part of the community. Its members work mainly in higher education establishments or research centers, and they belong to recognized national or international scientific societies. Their work progresses and their results become clearer through criticism and judgment of peers. Over time, the process can lead to a more or less extensive consensus.

Does consensus necessarily lead to objective knowledge? Not always, because scientific results are fundamentally open to question. According to Oreskes, however, “objectivity is likely to be maximized when there are recognized and robust avenues of criticism, […] when the community is open, non-defensive, and responds to criticism, and when it is diverse enough for a broad spectrum of opinions to develop, be heard and adequately considered ”.

In the light of these principles, one can analyze the three examples of bankruptcy mentioned above. Thalidomide has been prescribed for anxiety, insomnia and nausea problems without having previously been tested in pregnant women and, therefore, without any consensus on its safety. In the aftermath of the tragedy, several countries made drug approval more stringent. The launch of Challenger was authorized despite the advice of engineers warning their superiors against the danger of going ahead at too low an ambient temperature. Regarding the pandemic preparedness assessment, the experts whose opinions were sought came overwhelmingly from the health sector. The political and cultural dimensions of the problem were poorly represented, although these factors were decisive in each country’s response to the crisis.

Peer judgment

It is estimated that more than 95% of climatologists believe that the planet is warming and that the warming is mainly of anthropogenic origin. This consensus, which Naomi Oreskes analyzed in 2004 for the journal Science, is based on thousands of peer-reviewed scientific articles and is expressed in the reports of the Intergovernmental Panel on Climate Change. The IPCC comprises scientists from many countries and its reports are themselves subject to peer review.

What about the opinion of those who question the anthropogenic origin of global warming? This opinion is conveyed overwhelmingly by scientists who are not climate experts or by others whose judgment is probably colored by close links with the oil industry. It does not therefore constitute a serious questioning of the consensus. Almost all experts agree that if we do not drastically reduce greenhouse gas emissions, the global average temperature will rise several degrees by 2100, with severe environmental consequences. The modeling leaves room for certain quantitative margins, before which Oreskes suggests the following answer: “In evaluating a scientific assertion which has social, political or personal consequences, an additional question must be considered: what are the stakes of an error in a one way or the other? How does the risk of accepting a statement that turns out to be false compare to the risk of rejecting a statement that turns out to be true? “

Can we trust the experts in a situation like the current pandemic? With regard to vaccines, the consensus is clear: they offer immunity in the order of 90%, while they only cause serious reactions in about one in 100,000. Other decisions, on the other hand, are more complex to make: “the more socially sensitive an issue, the more open and diverse the community that examines it needs to be”. A decision about containment, for example, requires input from epidemiologists, psychologists, educators and economists. These specialists, even with the best intentions, will probably approach the question with different values. Oreskes argues that the idea of ​​the scientist analyzing facts without regard to his values ​​has frequently proved to be a myth. “A community with diverse values ​​is more likely to identify and challenge prejudices within or disguised as scientific theory. Joined to the consensus, a more transparent attitude of scientists about their values ​​and, why not, a touch of modesty could strengthen public confidence.

Suggestions ? Write to Robert Dutrisac: [email protected].

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