Stanford Encyclopedia of Philosophy
https://plato.stanford.edu/index.html
A very thorough, peer-reviewed resource about all things philosophy, curated by professional philosophers and other specialists.
The Internet Encyclopedia of Philosophy
Another excellent peer-reviewed resource about philosophy. Unlike the Stanford Encyclopedia of Philosophy, it includes a specific entry dedicated to Plato's The Republic.
Michael Sandel's Justice Course - A YouTube Playlist
https://www.youtube.com/watch?v=kBdfcR-8hEY&list=PL30C13C91CFFEFEA6
This recording of Harvard political philosopher Michael Sandel's widely-acclaimed course on justice can...
