Melvyn Bragg presents a regular discussion programme on Radio 4 that explores the history of ideas. There's a full archive going back 7 years which, if you have stream capturing software (like this, free for 15 days), can be saved as a file and listened to later (and burnt to CD or turned to MP3 with the right so tools).

I've been listening to:
- alchemy
- faeries
- fisher king
- holy grail
- pagan renaissance
- renaissance astrology
- renaissance magic
- victorian pessimism
- victorian realism
- witchcraft

I don't know if it's available outside the UK.