Human knowledge is vast, and we are all ignorant about a great many things. We strive to give our citizens a broad education so we all know at least a little about many subjects, but there are limits to our knowledge and experience. Most people are aware of their limits and respect the insight that comes from specialized study and training in a particular subject. As we grow and learn we develop ideas about how the world works. Many of us learn to modify those ideas if we acquire new knowledge that contradicts those ideas. This is a fundamental principle of the scientific method, which has proven to be the most effective and reliable method of “knowing” ever developed.
But some people, once they have acquired a little knowledge, lose all humility and think their “common sense” is all they need to make their way in the world. This often results in very rigid ideas about the world, people, and politics, based on a simplistic view point that ignores or denies conflicting facts and ideas, and with a distain for informed opinions (false “elitism”). It is both sad and pathetic when these people make a public spectacle of themselves by arguing on subjects they clearly know very little about. I call them the willfully ignorant (WI).
Arguing with them is extremely frustrating. They are often misinformed or grossly under-informed, yet stubbornly reject any knowledge that conflicts with their opinions or “common sense”. They often have no clue how little they know or how wrong their facts are(Dunning-Kruger Effect). They believe their conclusions follow logically from their premises (which themselves are often false) even though they can’t identify the most basic logical flaws in any argument (I once received an email from a WI which contained 8 different logical errors in a single sentence). They rarely acknowledge when their logical or factual errors are exposed. They ignore it and repeat the error, change the subject, or attack you for contradicting them. No matter how thoroughly you present your case they are unlikely to concede the argument or acknowledge any flaws in their thinking. In fact the WI often state that there are no facts that could change their opinion.
This makes debating a WI a futile exercise. Nevertheless it can be personally rewarding if you consider it a chance to hone your own argumentative skills. If it is a public discussion you also have the opportunity to educate the bystanders. Do not get emotionally involved. Stay detached and logical, even if they attack your character and intelligence. Remember that you are unlikely to change their mind, but you will be more convincing to others if you stick to facts and reasoned argument.
Stay focused on one or two points. Changing the subject is a common technique to avoid acknowledging factual or logical errors. Do not let them move on until they admit they were wrong or they defend the point.
Do not let them put words in your mouth. A common tactic is to twist something you said into something different (or to “assume” or “imply” you said something you didn’t) and to then refute that. This is known as a “straw man argument”. It may be an innocent mistake, but is often a deliberate and dishonest tactic.
Be ready to challenge the “argument from ignorance” where the arguer’s ignorance of some fact is used to “prove” their point. For example, “Since you can't prove what that light in the sky was, then it must be aliens from Planet X.” If you don’t know what it was you have no reason for concluding what it was. Or, “You must be in favor of carbon caps since I don’t know anyone who believes in global warming that doesn’t.” That’s straw man and argument from ignorance combined – the WI are certainly resourceful. The fact that you are ill informed does not prove anything except your own ignorance.
Be on the lookout for contradictions. My favorite is a non-biologist stating the since Darwin did not get a degree in biology then his biological theory can’t be valid. If we accept that flawed premise (only people with biology degrees can formulate biological theories) then the speaker herself (a non-biologist) cannot judge the validity of a biological theory. Contradictions are common, but often subtle.
Finally, do not attack the person’s character or intelligence. Stick to the facts under discussion, even if they start calling you names. Attacking the person rather than his arguments is known as the ad hominem fallacy. Ad hominem attacks can be brutal and a strong emotional reaction is understandable. But take a deep breath, confine your remarks to the observation that a personal attack does not negate your facts, and restate the point they were trying to avoid.
Remember that you are unlikely to sway a person whose conclusions are based on deeply held beliefs, myths, or opinions rather than on facts and logic. But if your goal is to refine your own arguments and beliefs or to convince others of the validity of your position, these guidelines will help you succeed.