Not the bully kind of superstitious "authority", but the supposed expert kind of authority. They can be wrong, too.
Statists are particularly fond of the Argument from Authority. They are prone to fall for that sort of thing and believe everyone else should, too.
Just because some philosopher carefully dreamed up a justification for the State doesn't make his justification valid. That he lived long ago and people still fall for his nonsense doesn't add weight to his ideas.
And it doesn't make you smart, cultured, or educated to quote him and believe his justifications.