A wise teacher came among a community of the blind to teach them how to cure their blindness. His cure was not perfect, but when applied fully, it restored much of their sight.

The teacher was with them only a short time. When he left, only a few had learned incomplete forms of the cure and had only partially restored their own sight.

As news about the teacher’s cure spread, his few followers began to teach the different forms of the cure each had learned, as best they could remember. Some cures were better than others, but none of them were the teacher’s complete cure. Many essential parts of the different cures remained the same, though, because it was obvious when someone offered a completely ineffectual cure. The people separated into groups based on which cure they used. Each group offered explanations for how the cure worked, but the explanations were mostly wrong. The truth was that no one knew how it worked.

A small minority of the people had a different form of blindness that was incurable. After applying the cure, they still saw only darkness. Having been blind their whole lives, they could not even understand what it was to have sight—their abstract understanding of the descriptions of others was a poor substitute for personally experiencing the light of sight. They assumed that the others who raved about the cures were liars; that because the cure did not work for them, it was a fraud. They mercilessly criticized the cure and the cure-followers, trying to find every possible flaw and point them out. They convincingly questioned the groups’ explanations for how the cure worked, showing how they did not make sense. If the explanations were clearly wrong, they argued, then the cures must also be fake.

More and more people started to recognize that the different groups’ cures did not work as well as promised. They listened to the criticisms of the incurably blind and started noticing how much they still could not see and that many things were blurry and unfocused. They suspected there were many things to be seen that they were not even aware of. They wondered if what they had been perceiving was really an illusion.

Out of disillusionment and frustration, they stopped applying the cures they had been using. Their blindness returned, for the cures required consistent application to remain effective. These newly re-blinded people joined the incurably blind and spent their time attacking the groups and the teacher, rather than seeking out a better cure. As criticism against the cures grew, increasing numbers of people turned back to blindness.

Those who persisted in their new blindness raised their children without knowledge of the cure. Many of these children lived out their lives in unnecessary darkness, not even fully realizing what they lacked.

Some of those who rejected the cure remembered the light they used to perceive and eventually realized that an imperfect, un­explainable cure was better than none at all. They still felt dissatisfied with the imperfect cure they had, however, and decided to seek a better one, rather than continue forever in blindness or in partial sight. They learned from each other and studied the groups’ different versions of the cure, looking for commonalities. Each person found that while many of these commonalities were things his own prior group already taught, some were things his group did not have. As each person tried the things that were new to him, his eyesight often improved greatly.

Next, they tried less-common parts of the different group’s cures that seemed compatible with what they knew to work. (Some of these came from the original teacher, and some had been created over time within individual groups as they differentiated.) They also added new things that appeared consistent with the other parts they knew to work and thus offered good prospects for supplementing or improving it. Often, the things they tried had little effect or even made their eyesight worse. Occasionally, though, some of these new additions improved their eyesight. They kept track of what worked and what did not. Eventually, they created a cure that was better than the cures applied by the different groups and better even than the teacher’s original cure. They even started to figure out how some parts of the cure worked

They tried to explain to the others what it was like to have pure, full sight, but the blind and partial-sighted could not understand. The partially sighted persecuted and maligned this new cure, claiming that the old groups’ cures already provided full sight. They slandered those seeking a new cure, calling them liars and deceivers. They accused them of betraying the teacher and the established groups of which they had once been members. The incurably blind and the disillusioned who had become blind continued to insist that there was no such thing as blindness, and thus also that this new cure was a fraud and that its proponents were dangerous deceivers.

Those who had created a better cure formed their own group focused on the cure and on protecting themselves from the persecutions of the others. They continued to refine and improve the cure. Their group of cure-followers slowly grew. It attracted wise and practical people who were better at discerning truth from false­hood and between what is relevant and irrelevant. Their example helped many people, especially the children of those who had chosen blindness and had never been taught a cure, to find their way to the best cure, and to sight.