The Shikker Dovid notes the following:
The cave story of Shimon Bar Yochai is central to Lag B’omer. On Daf 33b of masechest Shabbos, it is related that Shimon Bar Yochai and his son spend 12 years in a cave learning and living in only a spiritual realm. No contact with outside world. When he finally emerges at the advice of the prophet Elijah, he sees men working in a field. He is so outraged by their actions, he shoots a look at them and kills them. Hashem tells him to go back to the cave.
In Plato’s republic there is also a cave idea. The following is the information about the cave Plato lets Socrates describe a group of people who have lived chained to the wall of a cave all of their lives, facing a blank wall. The people watch shadows projected on the wall by things passing in front of a fire behind them, and begin to ascribe forms to these shadows. According to Plato’s Socrates, the shadows are as close as the prisoners get to viewing reality. He then explains how the philosopher is like a prisoner who is freed from the cave and comes to understand that the shadows on the wall do not make up reality at all, as he can perceive the true form of reality rather than the mere shadows seen by the prisoners.
The Allegory may be related to Plato’s Theory of Forms, according to which the “Forms” (or “Ideas”), and not the material world of change known to us through sensation, possess the highest and most fundamental kind of reality. Only knowledge of the Forms constitutes real knowledge. In addition, the Allegory of the Cave is an attempt to explain the philosopher’s place in society: to attempt to enlighten the “prisoners”.
To the Shikker Dovid, the cave has the potential to be a wonderful refuge for spirituality, .. or (gd forbid)a prison of intolerance. The work in life to to use the cave as an enlightened refuge. To venture into the world and retreat back into the cave for spiritual reflection. Plato’s cave has the potential to be a prison. The reality of Shimon Ben Yochai’s cave and Plato’s cave is that both are needed.