In A Good Man Goes to War, Madame Kovarian describes the conflict between the Doctor and the Silence as an "endless, bitter war." It's been suggested that this war could go all the way back to the Doctor's first incarnation, but due to the memory-defying abilities of the Silents, he doesn't remember it. What events that occured in the classic series could have been instigated by the Silence to get the Doctor out of the way? 82.2.136.93talk to me 23:19, April 1, 2012 (UTC)
When people see the Silence, they usually get some kind of memory of previous encounters with them, so the Doctor probably never directly faced the Silence in the past. However, given their powers of post-hypnotic suggestion, they could be responsible for pretty much any of the enemies in past episodes.Icecreamdif talk to me 23:40, April 1, 2012 (UTC)
Maybe the Doctor hasn't had these previous encounters with the Silence yet? The man's a time traveller. 94.72.208.131talk to me 12:26, April 2, 2012 (UTC)