By using comparisons he makes it easier for people to understand why his arguments are sound. An example can be his Cave Story which is in it's entirety a comparison, or an allegory, for finding ways to enlighten yourself and to see what the world is actually like.
According to Plato's argument uneducated people looks like the ones in the cave. Because the life is lived when it is learned. Plato draws the comparison between material world and the world of ideas, emphasizing the importance of the latter. He also claims that mind has to be freed, it has to be able to perceive thing how they are. With restricted mind, individual can only obtain the shown part of something. He cannot learn everything.
