The above quote is fairly well known in some circles, but there’s one glaring problem: it’s not true.
Really, this becomes an exercise in hypothesis testing. The quote is a null hypothesis: a person will never be reasoned out of a belief they weren’t reasoned into. To reject the null hypothesis, all we need is one example of this happening.
There are a number of unreasonable beliefs out there to choose from where a person may have come to their senses: conspiracy theories, anti-vaxxers, belief in psychics, etc. But many of these utilize a form of reason (rationalization, or motivated reasoning). They use faulty methods and dishonest selection of evidence, but it’s still an attempt at reason.
At the risk of offending readers, the primary example of something a person is not “reasoned into” is religion. The single greatest predictor of one’s religion is the religion of their parents. The second greatest predictor is the geography into which a person is born. Religion is overwhelmingly an inherited trait.
And yet, people are capable of using reason to escape insular (Amish) and cultish (Scientology) beliefs systems. Despite being born into these belief systems, indoctrination from an early age, active avoidance of conflicting ideas or information, and the threat of shunning from friends and family, there are still people who use reason and critical thinking to eventually shake themselves free of their mental imprisonment.
It’s incredible, commendable, and brave in the face of the social retribution they face. But most importantly it discredits the quote of the day.
I understand the sentiment behind the quote. It can be frustrating to engage with a person that either can’t or won’t see reason and it becomes easier to simply “write them off” as a lost cause. Leon Festinger’s book When Prophecy Fails details the mental gymnastics of a UFO cult when faced with a failure of their prediction. Rather than admit they had been wrong, or believed something false, they pivoted the claim and continued in their (revised) belief anyway.
This can be maddening to see from the outside.
One thing to keep in mind is that beliefs are intertwined and seldom stand alone. This is one reason for the persistence of a belief in the face of damning evidence, and what makes leaving a belief such a difficult feat. For example, one’s opinion on capital punishment has strong correlations with opinions on prison policy and 2nd Amendment rights. Opinions on foreign policy and military matters tend to correlate, as well. Our beliefs are like a ball of yarn, or a loose knot comprised of multiple threads- it is very difficult to tug on one isolated thread (belief) without jostling the whole thing. Separating beliefs from one another can be time-consuming, distressing, and a lot of hard work! But it can be done if the belief holder wants to put in the effort.
It would be more accurate to say that it is useless to try and reason with somebody if they refuse to consider and revise their beliefs (doxastically closed).