•Why it earns a slot
Why it earns a slot: it invents the noble lie, the cave, and the ring of Gyges in one sitting, three thought experiments still doing the argumentative work of modern politics, ethics, and media theory.
Socrates gets stopped on his way home from a festival and ends up building an entire imaginary city just to answer one question: is it better to be just or to get away with being unjust.
This distillation is written from the freely available original, which is always the better read when you have the time: Project Gutenberg.