perspicacious, sagacious, sapient -- (acutely insightful and wise; "much too perspicacious to be taken in by such a spurious argument"; "observant and thoughtful, he was given to asking sagacious questions"; "a source of valuable insights and sapient advice to educators")
clear-eyed, clear-sighted, perspicacious -- (mentally acute or penetratingly discerning; "too clear-eyed not to see what problems would follow"; "chaos could be prevented only by clear-sighted leadership"; "much too perspicacious to be taken in by so spurious an argument")
(Sound)
