People have lots of arguments (at least I do) about politics and \nhuman affairs. In most cases we have no chance of persuading anyone, as\n we don\u2019t form beliefs based on logical thought.<\/p>\n\n\n\n
\u201cBeliefs\u201d are for religion. In logical thought we call them axioms. \nHowever, in most arguments we don\u2019t question our axioms and believe the \nconclusions, however shaky the line of reasoning. It would be nice to \nsee decisions made on the basis of evidence, but too often the decision \nis made based on prejudice and the reasoning tailored to the conclusion.\n No group is immune (although some may be more prone to it than \nothers).<\/p>\n\n\n\n
I find it helpful to ask myself \u201cwhat evidence would cause me to \nchange my mind about a subject?\u201d. If I know what to look for then I can\n question my conclusions independently of the \u201creasoning\u201d that created \nthem.<\/p>\n\n\n\n
Take Global Warming \u2013 as an example.<\/strong><\/p>\n\n\n\n We have all sorts of reasons for concluding that greenhouse gases \ncause heat retention in the atmosphere, and that if there were no \ngreenhouse gases the earth would be many degrees cooler. There are a \nfew hidden axioms there, but it can be taken as near to a \u201cfact\u201d as \nscience gives.<\/p>\n\n\n\n The global climate record is showing warming based on temperature \ngauges and proxy measurements. It is therefore logical to conclude that\n greenhouse gases are causing the current warming. Alternatively we \nhave to show both:<\/p>\n\n\n\n All that remains is to measure the coefficient of warming. From that\n we can predict how much warming to expect in the future given that we \nkeep treating the atmosphere like a sewer.<\/p>\n\n\n\n Not so fast!<\/strong><\/p>\n\n\n\n The scientific method goes: evidence, theory, prediction, measurement\n (rinse and repeat). So far we have shown the first 3, how have \npredictions made in the previous decades matched reality? The answer is\n well enough (within the uncertainties that come with climate models) \nbut not conclusive enough to be considered \u201cscientific fact\u201d.<\/p>\n\n\n\n So if not \u201cscientific fact\u201d then what? We make all sorts of public \npolicy on evidence that is much weaker than the evidence for global \nwarming. (just look at economics, which is little better than \nguesswork). We might think of the difference between criminal vs civil \nlaw. In criminal law we are looking for \u201cbeyond reasonable doubt\u201d (yet \nwe use evidence which is much weaker than the evidence for global \nwarming). In civil law we have to allow a decision on balance of \nprobabilities. In public policy we have to balance the costs and risks \nof BAU vs the costs of action. Physics doesn\u2019t say anything about the \ncosts (that is economics) but please use the best available physics to \nmake your estimates.<\/p>\n\n\n\n So what would make me doubt global warming?<\/strong><\/p>\n\n\n\n It turns out in this case the first bullet point is crucial, so long \nas at least one of the others stands. So if you want to convince me \nthat global warming is bogus, show me real evidence that the physics is \nwrong!<\/p>\n\n\n\n If you are convinced that human activity is not warming the planet, \nthen I challenge you to consider what evidence would make you change \nyour mind.<\/p>\n","protected":false},"excerpt":{"rendered":" People have lots of arguments (at least I do) about politics and human affairs. In most cases we have no chance of persuading anyone, as we don\u2019t form beliefs based on logical thought. \u201cBeliefs\u201d are for religion. In logical thought we call them axioms. However, in most arguments we don\u2019t question our axioms and believe … <\/p>\n