The allegory of the cave aims to highlight the state with education or lack of it, is our nature, that is, the most men it is relative to the knowledge of truth or ignorance. Thus, prisoners represent the humanity, slave and prisoner of his ignorance and unaware of it, clutching customs, opinions, prejudices and false beliefs forever. These prisoners, like most men think they know and feel happy in their ignorance, but are in error, and take for real and true what which they are nothing but mere shadows of manufactured objects and echoes of voices.
This aspect of Plato's myth serves to exemplify, in a language full of metaphors, the distinction between sensible and intelligible world (Ontological dualism), and the distinction between opinion and knowledge (dualism epistemological). The main function of the myth is, however, expose the process to be followed by education of the ruling philosopher, central theme of the book VII.
This process is represented by the travel of the prisoner released from inside the cave to the outside world, and ends with the vision of the sun. He Myth suggests that education is a long and costly process, fraught with obstacles and therefore not accessible to anyone. The released prisoner must gradually abandon its old and false beliefs, prejudices linked to custom; You must break with his former life, convenient and comfortable, but based on deception; It has to overcome fears and difficulties to be able to understand the new reality that is before their eyes, the more real and authentic than previous. Hence, the prisoner must be "required", "forced", "dragged" by a 'rough and steep climb "and slowly get used to the light outside, to attain knowledge of the truly real, eternal, immaterial and immutable Ideas. But do not stop there the task of the philosopher once formed in the knowledge of the truth, must "descend into the cave again" and, although initially be displayed awkward and also need a period of adjustment, must deal with human affairs, own the sensible world (the policy, organization of the state, the courts, etc.) It is very important to relate this myth with general knowledge about philosophy of Plato, especially the theory of Ideas, the distinction between knowledge and opinion, etc., and pay special attention to interpret correctly abundant metaphors of myth ( "vision", "chains", "the Interior things "," things above "," sun ", etc.) translating the respective concepts of Platonic philosophy.

 

Plato, Republic, Book VII, Ed. Gredos, Madrid, 1992 (Translation of C. Eggers Lan).