In Plato, at this point puts the

In the beginning of the Republic Book VII, Plato talks of an imaginary situation in which
humans are. He puts humans in a cave, locked up, only able to see what is in
front of them. There is a wall behind them, on which are people carrying every
material there is. There is a fire behind the wall, and casts the shadows of
the materials onto the side of the cave that is in front of the humans. Plato
says that “…the prisoners would in every way believe that the truth is nothing
other than the shadows of those artifacts” (515c). When one is freed, somehow,
and sees the things themselves, he sees them more correctly; however, he’d be
at a loss and believe that the shadows were the true things. And when he is
pulled out of the cave to the sunlight, he would be unable to see them until
his eyes are adjusted, Plato says. When the man sees that the sun is the cause
of all things he used to see, and went back into the cave again, his eyes
would, again, be unable to see, and be welcomed with ridicule by the ones who
do not know about the sun, or even the light in the cave. Plato, at this point
puts the conclusions derived from the divided line together with this and says
that the visible realm is the cave, the light of the fire is the sun. As the
soul transcends above the cave and is able to study the things above the cave,
he sees the things in their true nature. The sun above the cave is “the good”
itself, and it is the last thing to be seen, according to Plato. For Plato,
therefore, the task of the philosopher is to see the first principle, the good;
and, come back to the cave and “…compel the best natures to reach the study we
said before is the most important, namely, to make the ascent and see the good”
(519c-d). The ascent here, is the philosophy itself; the philosopher is one who
completed the ascent and is now back in the cave, it is someone who can
distinguish between the forms and the images, it is someone who knows the real
cause of this.