When Is it Appropriate to Challenge the "Consensus"?
Discovery Institute senior fellow Jay Richards has an excellent piece at The American titled, "When to Doubt a Scientific 'Consensus'," that gives 12 criteria to help us decide whether it's appropriate to doubt a particular "consensus." Richards of course notes that the very term "consensus" is often used to shut down scientific debate--but that hardly means the scientific "consensus" is necessarily wrong. Indeed, some wrongly challenge the consensus when it ought to be affirmed. Richards threads this needle carefully, explaining why we must carefully examine the scientific, sociological, rhetorical, and political dynamics of a debate to determine if the consensus deserves our assent, or our skepticism:
Anyone who has studied the history of science knows that scientists are not immune to the non-rational dynamics of the herd. Many false ideas enjoyed consensus opinion at one time. Indeed, the "power of the paradigm" often shapes the thinking of scientists so strongly that they become unable to accurately summarize, let alone evaluate, radical alternatives. Question the paradigm, and some respond with dogmatic fanaticism.Many of Richards' criteria are clearly applicable to the debate over intelligent design (ID) and neo-Darwinism. For example, Darwin's defenders make heavy use of personal attacks, and Richards suggests we ought to consider skepticism "When ad hominem attacks against dissenters predominate." Likewise, Richards' criteria of "When scientists are pressured to toe the party line" or ""When publishing and peer review in the discipline is cliquish" also have immediately obvious relevance to the ID-evolution debate.
We shouldn't, of course, forget the other side of the coin. There are always cranks and conspiracy theorists. No matter how well founded a scientific consensus, there's someone somewhere--easily accessible online--that thinks it's all hokum. Sometimes these folks turn out to be right. But often, they're just cranks whose counsel is best disregarded.
So what's a non-scientist citizen, without the time to study the scientific details, to do? How is the ordinary citizen to distinguish, as Andrew Coyne puts it, "between genuine authority and mere received wisdom? Conversely, how do we tell crankish imperviousness to evidence from legitimate skepticism?" Are we obligated to trust whatever we're told is based on a scientific consensus unless we can study the science ourselves? When can you doubt a consensus? When should you doubt it?
Your best bet is to look at the process that produced, maintains, and communicates the ostensible consensus. I don't know of any exhaustive list of signs of suspicion, but, using climate change as a test study, I propose this checklist as a rough-and-ready list of signs for when to consider doubting a scientific "consensus," whatever the subject. One of these signs may be enough to give pause. If they start to pile up, then it's wise to be suspicious.
But what about Richards' first criterion: "When different claims get bundled together"? Does it apply to the ID-Darwin debate? According to Richards:
Usually, in scientific disputes, there is more than one claim at issue. With global warming, there's the claim that our planet, on average, is getting warmer. There's also the claim that human emissions are the main cause of it, that it's going to be catastrophic, and that we have to transform civilization to deal with it. These are all different assertions with different bases of evidence. Evidence for warming, for instance, isn't evidence for the cause of that warming. All the polar bears could drown, the glaciers melt, the sea levels rise 20 feet, Newfoundland become a popular place to tan, and that wouldn't tell us a thing about what caused the warming. This is a matter of logic, not scientific evidence. The effect is not the same as the cause.
There's a lot more agreement about (1) a modest warming trend since about 1850 than there is about (2) the cause of that trend. There's even less agreement about (3) the dangers of that trend, or of (4) what to do about it. But these four propositions are frequently bundled together, so that if you doubt one, you're labeled a climate change "skeptic" or "denier." That's just plain intellectually dishonest. When well-established claims are fused with separate, more controversial claims, and the entire conglomeration is covered with the label "consensus," you have reason for doubt.
Indeed, this criterion is highly applicable to the debate over Darwinism. Darwin's defenders often refuse to recognize that Darwin-skeptics have nuanced positions, affirming that evolution has occurred (and continues to occur) occur but typically doubting the importance of the causes being given, and often doubting the scale of evolution possible from material processes alone.
So the "bundling of claims" occurs dramatically in the Darwin debate as well, where modern day Darwinians bundle (1) "change over time," (2) "common descent", and (3) "random mutation + natural selection as the primary mechanism driving change" into one claim -- "Evolution" -- but they refuse to acknowledge the nuanced positions of critics who may accept (1) and/or (2), but doubt (3).
Finally, it's worth noting that Richards final criterion -- "When we keep being told that there's a scientific consensus" -- is perhaps the most important one. The late Michael Crichton would agree. As he eloquently observed, "The work of science has nothing whatever to do with consensus. Consensus is the business of politics. ... There is no such thing as consensus science. If it's consensus, it isn't science. If it's science, it isn't consensus. Period. ... Consensus is invoked only in situations where the science is not solid enough. Nobody says the consensus of scientists agrees that E=mc2. Nobody says the consensus is that the sun is 93 million miles away. It would never occur to anyone to speak that way."