Percy Bysshe Shelley

Percy Bysshe Shelley was an Earth poet. He wrote, "All spirits are enslaved that serve things evil".

Captain Jean-Luc Picard quoted this line in a conversation with Armus. Picard's point was that to do the bidding of Armus would enslave the crew of the USS Enterprise (NCC-1701-D). Armus took the quote literally and argued that he wasn't a servant of evil, he was evil itself.