In his work Republic, Plato presents the allegory of the cave, which is one of the best-known philosophical allegories. Plato describes the process of gaining insight and the problems that come with it.
Plato describes the unenlightened man as shackled to a wall, deep inside a dark cave. His head is fixed in a certain position, such that he can only see the opposite wall. Further up in the cave, there is a fire that casts its light down onto the wall the man is facing. On the levels between the man and the fire, there are people carrying objects, and these objects cast shadows on the wall. Far above the fire, there is the entry of the cave, where the blindingly bright sunlight of the day can be seen.
Plato explains that the man must necessarily believe that the shadows the objects cast onto the wall must be reality, since he is unable to see anything but these shadows. If there were several men, all of them shackled to the wall, and if they were able to discuss what they see, they would surely agree that the shadows are reality.
If one of them were to be freed, and able to turn his head and to see the light above as well as the objects that are being carried around in front of the light, he would be in pain from moving his body for the first time, and blinded by the brightness of the light. His paining eyes would drive him back to the shadows, and he would cling to the belief that the shadows are reality. If he were dragged into the sunlight, against his will, he would be in pain, and, blinded by the sunlight, unable to recognize any of the objects that he is shown as real. Only after some time he would get used to the light, and he would be able to see reality.
Now, however, he would consider himself blessed for having left the dark cave, and he would pity those who are still shackled to the wall, down in the cave. Thinking back to the empty discussions he had about the shadows of the objects and the opinions about them, he would rather be a poor beggar than go back to ignorance.
If the man were to go back into the cave, he would be unable to see, since his eyes are now used to the brightness of the day, and the people down in the cave would make fun of him and agree that he ruined his eyes when he left the cave. The man would have to argue about the shadow of truth with people who have never seen truth itself. These people would agree that there is no point in leaving the cave, and they would attempt to kill anyone who tries to free them from their shackles.
In this allegory, Plato explains the difficulties of personal growth and of gaining insight. We are all attached to our opinions about the world and ourselves, and we like to believe that they accurately represent reality. But the fact is that it is impossible to see reality directly, our knowledge is always incomplete, our perspective is always limited to a certain angle. From time to time we run into trouble because of our limitations. We suffer, because we have to see things from a new angle, which is uncomfortable and stressful, but after a while we get used to it, and we enlarge our perspective. Then, we may look back to our old selves, and we are happy that we left some of our limitations behind. Anyone who embarks on a journey of personal growth is familiar with this experience.
Plato also points out that, if we manage to progress very far on the path of personal growth and insight, our behavior may appear unintelligible and strange to ordinary people. It may even be regarded as insane, and we may make a fool of ourselves. For example, in modern society, a certain degree of predatory self-interest is regarded as normal and may even be lauded as “persuasiveness” or “assertiveness”. Someone who has transcended self-interest to a certain degree, and who is motivated by compassion and concern for others, may be exploited, and ridiculed as naive.
The allegory also contains a warning. Many people prefer ignorance, they do not want to make the effort to grow, or they are not ready yet, and they fear truth. If you approach them with a truth that challenges their limitations and threatens them, they will fight, to defend their worldview. Aggression against those who have freed themselves of ideological shackles is the hallmark of all totalitarian systems, but in any community there is some sort of ideological mainstream with certain limitations, and those who confront these limitations are at risk of being ostracized and scapegoated. This is what happened to Plato’s teacher Socrates, who was sentenced to death, essentially for causing mischief with his free thinking.