Part two of our week of ghosts is all about one spirit – this time, a poltergeist. People have been arguing over this one since the 1660s, including some prominent skeptics and supporters.
Research:

SYMHC Classics: Gustave Courbet
40:51

Behind the Scenes Minis: Oh, Kropotkin!
17:28

Peter Kropotkin's Mutual Aid, Part 2
49:57