Consensus by jury

Science, we are constantly reminded, does not proceed by consensus. And indeed it doesn't.


Science proceeds according to the evidence.  However, as more evidence accrues, it becomes clearer and clearer that the idea being tested is correct, or at least the best explanation available at the moment.  A consensus accretes around that idea and science and scientists accept that it is correct.


In the fields that I studied a little while ago, the description of the action potential in a neuron is consensus because it is extremely unlikely that the basics of the physical chemistry involved will be found to be wrong.  Perhaps in one or two animals but the basics will be correct. And those neurophysiologists who study the action of neurons, there is barely likely to be a mention of whether or not they accept the current theory of action potentials.  They just get on with improving our understanding until its polish gleams.


Our denier friends don't like the idea of consensus.  They don't like the idea that scientists either agree with the evidence or they don't.  They don't like the thought that more and more scientists cluster around and agree an understanding.  It would be weird if scientists didn't work like that.  It would be weird if they all decided to accept different ideas and no one agreed with anyone else. 


It is how our legal system works.  When tried by a jury of my peers, I expect them to assess the evidence and come to an understanding of who was responsible for the particular crime.  I expect them to come to an agreement.  After all, the evidence can only point one direction, depending upon how good the evidence is. 


A unanimous verdict of the jury is a 100% consensus.  11 to 1 is 91.67%. 10 to 2 is 83.33%. 


83.33% consensus is good enough in some trials to secure a conviction. 


I think 97% is good enough consensus to allow us to say that global warming is caused by humans.