Any argument requires premises that it assumes and does not prove

Are Your Political Opponents Crazy? by Gary Gutting

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.