Opposing sides in political debates often characterize one another as crazy, or a bit more politely, “irrational.” John McCain, for example, recently said that the view of opponents of the debt-limit increase was “worse than foolish” and “bizzaro.” Paul Krugman suggested that President Obama’s desire to compromise on the debt-limit might be “obsessive and compulsive.” Even Elizabeth Drew, reporting on the debt-limit process, writes, “Were they all insane? That’s not a far-fetched question.” In less vivid terms, the claim is typically that a rival group’s thinking is dominated by a mind-muddling ideology that cannot be supported by rational argument. People are, of course, frequently irrational; they ignore obvious facts or make silly mistakes in reasoning. But the mere failure to support some of your basic claims with good logical arguments does not show that you are irrational. Any argument requires premises that it assumes and does not prove. We may construct a further argument for an unproven premise, but that argument will itself have unproven premises. That’s why even mathematics, the most thoroughly rational enterprise we have, begins with unproven axioms.
more from Gary Gutting at The Opinionater here.