The allegory is the story of a people who have been held prisoner in a cave deep inside a mountain. They have been there for so long that the cave has gradually become the only world they know.
The prisoners are laid in chains in that prison, that are fastened behind a wall in the cave, facing the rear of the cavern. This rock encrusted world is the only world they know. The only light they can see is the light from a fire that is maintained on the other side of the wall, which is reflected off the rocks of the cavern in front of them, and above them (see illustration). In this manner, their world has become a world of a faint glow of light and of huge shadows of objects that are passed in front of the fire. The shadows, which they all see with their senses can, thus become a reality to them that in part defines their world, that they react to.
Then someone manages to break away from the chains, and cautiously ventures to the other side of the wall, and with great amazement begins to observe the process that creates the shadows. The person who experiences this awakening becomes free in more than one sense. This self-freed prisoner sees the fire, and also sees the objects that obscure the light and thereby create magnified shadow images of the shape of these objects. The so freed prisoner begins to understand that the mythology of the world they had created for themselves was not real, but was merely a construct of their deduction from the limitations of their perception.
The freed prisoner also soon understands the fire to be the source of their light, contrary to the myths that the prisoner's had come to believe to be real. Also, in the distance behind that fire the freed prisoner discovers that there exists an exit from this cave of shadows and delusions. Behind this exit, that he or she ventures beyond, the freed prisoner discovers a whole new world, a world of blinding sunlight that this person soon understands to be the glorious nature of the real universe. Also, that self-freed person discovers at this threshold, entering into the sunlight, that he or she isn't a prisoner anymore.
With this profound allegory Plato illustrates the challenge that we all face, to resolve the great paradoxes of human existence. We live in a world of human thought that is defined by the limitations of what our senses are able to behold, and by the finity of the imaginary worlds that deduce from what we thus see. We bow to the shadows that the limited senses tell us is the reality of our being and our universe. But when we, like the prisoner, break free from the chains that bind our existence by binding our movement of perception; when we see the fire and the process that causes the shadows; when we begin to understand the processes of the real world and finally see the exit from the cave; then the whole cave experience becomes little more than just a shadow itself, of a bad dream.
This is in essence what Mary Baker Eddy discovered in February 1866 during the process of her healing from an injury that medical doctors had deemed to be ultimately fatal (see details). This experience brought her into the light of the real universe. She challenges us to replicate this process in our own lives. We must ask ourselves, therefore, what defines our world and the shape of reality for us? Do the shadows that we behold with our senses constitute reality, or are they but shadows? We must ask ourselves if it is possible to free ourselves from this narrowly perceived world, and to understand the processes behind the perceived finity that is conjured up by limitations of perception? The question then becomes imperative: Can we find the exit from the cave, which promises to be our portal to the real world? Plato suggested that we can, and Mary Baker Eddy proved this in her own life. She, like Christ Jesus, proved the universe to be spiritual, and discernable with a spiritual sense of reality.
As we uplift ourselves in this manner and begin to see with the mind what the sense cannot convey; as we look beyond the limits that confront us, paradoxically; we become like the prisoner who has shed the iron chains and understands the processes that create delusions that are all too often perceived as reality. Then, we too, can become really free.