Letter to the Editor - Monday, October 21: Forget consensus
THIS is in regard to the comment by Richard Somerville in the weekend Examiner that "97% of scentists (sic) agree".
With all respect, that statement is what's known as argumentum ad populum, which is "the basic idea is that a claim is accepted as being true simply because most people are favourably inclined towards the claim".
More formally, the fact that most people have favourable emotions associated with the claim is substituted in place of actual evidence for the claim.
A person falls prey to this fallacy if he accepts a claim as being true simply because most other people approve of the claim.
It is clearly fallacious to accept the approval of the majority as evidence for a claim.
For example, suppose that a skilled speaker managed to get most people to absolutely love the claim that 1+1 = 3.
It would still not be rational to accept this claim simply because most people approved of it.
After all, mere approval is no substitute for a mathematical proof. At one time, people approved of claims such as "the world is flat", "humans cannot survive at speeds greater than 25 miles per hour", "the sun revolves around the earth", but all these claims turned out to be false.
The consensus argument is a weak one. History is replete with examples of past consensus that have proven to be wrong.
This consensus argument revolves around something called the Duran Survey.
Thousands of questionnaires sent out to scientists and only 77 were returned - and 95% of those responded that humans are causing climate change. Not exactly a large sample rate.