Upon re-listening to this lecture from a past year I don’t think I can really improve on it, so in lieu of a new recording of the same old material I offer this: IR Liberalism.

Note that in order to get this to play with both the audio and the video at the same time you need to download the file to your computer, and then import it into iTunes (where it seems to work fine) or play it with QuickTime Player 7.6.6 (not the 10.1 version of the QuickTime player that ships with newer Mac computers — the older player is a free download from Apple’s website, and it works with every MacOS back to about 10.4, I believe. QuickTime Player 10.1 thinks that .m4a files are audio-only, so it doesn’t look for the video track.