The Committee for the Advancement of Scientific Skepticism (CASS) at the Centre for Inquiry Canada, in an effort to educate the public about the roles of critical thinking and the philosophy of skepticism, has produced a series of articles we have entitled “What is Skepticism?” Over four weeks we will be presenting them on Skeptic North and welcome your comments and discussion.
Last week we discussed the difference between science and the untenable position of scientism. This week’s article by Ryan A. Gray and Iain Martel of CASS discuss the philosophical conflict between ideological deniers and scientific skeptics.
Denial is Not Skepticism
- Everyone is a skeptic nowadays, or so it seems. From climate change to evolution to vaccination, large proportions of the population claim to be skeptical about many of the claims of mainstream science. So why are we, member of the skeptical community, not rejoicing? Why do we not join the mass of public opinion in skeptically rejecting claims of man-made climate change, or of the miracle of vaccination? The answer is simple: such “skeptics” are not true skeptics; mere denial is not skepticism.
- A skeptic, in popular discourse, is simply someone who denies a particular claim. But true skepticism, as espoused by philosophers and scientists for millenia, is more an intellectual attitude than a position on a specific issue. A skeptic is someone who always demands sufficient evidence or reasons before accepting a claim. This skeptical attitude – its opposite is credulity – leads skeptics to reject as unfounded any claim that cannot withstand the rigours of the scientific method, which includes controlled experimental testing. The more extraordinary the claim, the more rigourously it must be tested before a skeptic will be willing to accept it.
- The skeptical method leads to the rejection of many claims at the fringes of science. Take clairvoyance, for example. Many have claimed to be able to perceive the future, and have performed seemingly astounding feats of prediction. The skeptic, however, is not willing to accept such extraordinary claims on the basis of mere hearsay. Skeptics demand solid proof of clairvoyant ability, through carefully constructed experimental tests. And when purported clairvoyants fail these tests time and time again (or simply refuse to put their claims to rigourous test), skeptics conclude that clairvoyant claims are fraudulent.
- The scientific community also treats extraordinary claims from within its own ranks with this same skeptical attitude: witness the case of cold fusion, where a distinguished team of scientists claimed to have discovered the secret to unleashing almost limitless power from (heavy) water. The scientific community demanded proof before accepting these claims, and when the original experiments could not be replicated, the claims were rejected. Wishful thinking is not enough for belief, and most scientists today are doubtful that cold fusion will ever become a reality.
- But skepticism does not always lead to denial. Extraordinary claims require extraordinary evidence, but sometimes that extraordinary evidence can be provided. Einstein’s theory of relativity, which holds that matter can change the very shape of space and time, is an extraordinary claim, yet it has stood up to the most demanding of scientific testing. In countless experiments, the bizarre implications of Einstein’s theory, from light bending as it passes the sun to clocks slowing down at high speed, have all been strongly confirmed. And that most famous of all equations in physics, E = mc^2, was dramatically confirmed with the explosion of the first atomic bomb.
- How, then, should a skeptic approach the claims being made by the scientific community about global climate change? Here is a truly extraordinary claim, but what is the evidence? Scientists did not immediately accept the theory of man-made global warming when it was first proposed. Rather, it took decades of careful research, gathering data and developing models, before we reached the point today where the vast majority of climate scientists, having reviewed the evidence, are persuaded that this is a real and growing problem. They were persuaded by reams of data from multiple sources from around the world, which unambiguously indicate a rapid increase in global mean temperatures over the last century, reaching unprecedented levels in recent years; by sophisticated computer models, based on well-established basic science, which predict just such a warming pattern given the vast quantities of carbon dioxide and other pollutants which we have pumped into the atmosphere at increasing rates; and by the failure of any competing explanation of the climate record. The mass of evidence is, indeed, too vast and diverse to be adequately reviewed here. While legitimate doubt still remains about some of the details – such as the precise rate of future warming, and its effect on sea-levels, crops, etc. – the evidence points, with a very high degree of likelihood, to significant climate change in the coming decades.
- Now let us turn to the climate change “skeptics”. Are they just being more demanding than us in their skepticism? After all, nothing in science is ever certain; some room for doubt always exists. For that doubt to warrant disbelief in the face of all the positive evidence, however, skeptics would require significant contrary evidence, or a plausible alternative theory which fit the data. But climate change deniers have not provided any such evidence or theory (theories involving variations in solar activity simply don’t fit the data). Nor have they shown significant inclination to provide such evidence, generally being content to gesture frantically at any minor mistake, no matter how irrelevant, in the climate change literature. In fact, in denying climate change, these “skeptics” find themselves committed to claims no less extraordinary than the ones they deny, yet with far less evidence. Why, if there is no real climate change, is almost the entire scientific community in agreement? To answer this, we find deniers constructing elaborate conspiracy theories requiring the collusion of thousands of scientists in many countries in an elaborate hoax. But what could motivate such a hoax? How could it possibly be organised and maintained? A scientist can make a career by proving accepted theory wrong; why, if the skeptics are right, has some young revolutionary not emerged from within the climate scientists’ ranks to prove the establishment wrong? In the end, climate change denial requires a belief in far more unfounded claims than its acceptance. A true skeptic finds that it is the deniers’ conspiracy theories that are unbelievable, not the well-grounded science of the climatologists.
Iain Martel (CASS Co-chair)