I think Serling is saying that judging and not knowing and understanding something could cause chaos. Peopl e could be afraid of something and judge it before they actually understand it. Theres many examples throughout history that shows what judgement can do. For example in the 20th centurary white people were very predjudice against black people and still are. They judge by the color of their skin before they actually get to know the person. What he said pertains to what we learned because in the crucible many people were judge because of how they looked and acted and where they fitted in society. Beggers were easy targets for the towns people to accuse of being a witch because they saw them as an unsessary scum that  didnt have anything to do but witch craft.