Board Thread:Warhammer 40k General Discussion/@comment-91.224.27.226-20131031140001/@comment-24383134-20140106154053

I personally see the lose primarchs as having been placed on planets where they were raised in a manner that was in direct conflict with the Emperor's Creed. Maybe they were placed on planets where they had direct contact with Xenos and never really saw the Xenos as a threat? Maybe they were brought into a society where Chaos had deep roots and had corrupted them over time. Obviously something big had happened if they (GW) made it canon that the Emperor decreed the other Primarchs swear a vow of silence.