Board Thread:What If?/@comment-173.245.80.12-20140903054558/@comment-37017073-20190530204919

Brutegwaine wrote: Arthur knew that Gaius was a pseudo-follower and student of the old religion and magic. It was under Gaius's purview to tell Arthur that there was more to Lancelot than met the eye. Morgana used necromancy first, and Gaius did it to protect the kingdom. Of course these writers wrote it in a way that Lancelot fails the autenticity test because he doesn't know that Merlin has magic.

Arthur also knew that Gaius was supposed to have given up magic during the Great Purge in accordance with Camelot's laws, and reacted with very little understanding on the two occasions where that was called into question. He actually had to be persuaded not to just stand by and let Gaius burn in 2x07 (even after Gwen told him outright that Merlin had proof of his innocence), and he was fully prepared to condemn Gaius as a traitor in 4x07 when he was presented with evidence that Gaius had taken up sorcery again.

This is problematic because sorcery is the only means that Merlin and Gaius have of proving their claims about Lancelot. His lack of memory about Merlin's magic is what initially tips them off (well, it tipped Merlin off; Gaius was generally content to dismiss it as his being out of sorts from his ordeal), and they then arrived at the Shade conclusion by doing research in an illegal book about necromancy and by using a pentacle spell to confirm their theory.