In his textbook on critical thinking, David Hunter argues that only such an approach can be called reasonable in which
- I can clearly describe how I arrived at a given conclusion,
- I am able to reflect on the line of reasoning I used—I can consider whether it is reliable, when else it has been applied, and where its weak points are prone to error.
In short, reasonableness begins when I can step outside my own thinking and examine it much as I would assess the reasoning of, say, an Australian stockman trying to determine who stole his sheep: with interest, but without bias, and with a willingness to devote sufficient time.
But when was the last time you spoke with someone who spent an hour reflecting on how they arrived at a particular opinion, and whether that process was sound? In the overwhelming majority of cases, we feel no need to waste time on such exercises. Things seem perfectly obvious. The whole world appears to affirm that it is exactly so. Every minute brings further convincing evidence. Of course, there are people who see matters quite differently. That must surely be because they are foolish, fanatical, or thoroughly indoctrinated. What else could explain it?
This is how naïve thinking reveals itself. When you encounter someone with such firm convictions, you can be certain they will not devote even five seconds to examining how they reached them. Yet they will gladly spend hours arguing or assembling long lists of supporting evidence.
A reliable sign of naivety is the phrase “opinions based on facts.” More reflective minds understand that no such thing exists, nor can it.
This is not merely about intellectual shortcuts. It is also a matter of decency and integrity. It concerns whether, when confronted with an opposing view, a person pauses to ask: “Wait—how did I arrive at this? Might I have made a mistake?”—or whether he simply deletes his opponent from his contacts and moves on.