The story told in Alfred Hitchcock's classic thriller North by Northwest revolves around a man who doesn't exist. Cary Grant plays a debonair Manhattan advertising executive abducted by foreign spies who mistake him for an American counterintelligence agent named George Kaplan. Grant manages to elude his captors, only to be framed for the murder of a UN official. To clear himself, he sets off on a cross-country chase in pursuit of the elusive Kaplan, who is the only person he believes can corroborate his fantastic tale of being kidnapped by spies. While on the lam he falls in with one of Hitchcock's coolly glamorous blondes, played by Eva Marie Saint. He survives numerous close scrapes, both with the police and with the bad guys, including a famous encounter with a crop-duster in an Illinois corn field. Only late in the game does he discover that the elusive Kaplan is a nonexistent counterspy, created as a decoy to divert suspicion from the real American agent, Eva Marie Saint, whom Grant has mistaken for one of the spies.
Hitchcock, of course, was famous for a certain story-telling sleight of hand that he called a "MacGuffin." The term was coined by one of his scriptwriters to describe a plot device that moves things along without having any real significance to the outcome of the story or even any existence at all. In this case, the MacGuffin is the decoy counterspy George Kaplan. The term "MacGuffin" derives from a joke about two men on a train, one of whom asks the other about the strange package he is carrying. The other man tells him it's a MacGuffin, and explains that a MacGuffin is an apparatus for trapping lions in the Scottish highlands. When told there are no lions in Scotland, the man with the package says, "Well then, that's no MacGuffin."
There are those who believe that God fits the definition of a MacGuffin, but I suspect they may have gotten things backwards. Perhaps it is we who are the MacGuffin in thinking we have some real existence apart from God or even in thinking of ourselves at all. Who is this elusive "I" who is constantly interposing himself into the flow of life, imagining himself as protagonist in a story of his own making? Am I anything more than what I think, and where do such thoughts come from? They seem to arise out of nowhere, like champagne bubbles in an endless stream, before disappearing into the ether. I think, therefore I am, Descartes intoned. Is this the philosophic rock we wish to stand on when the storms of life swirl around us? Is this elusive "I" really anything more than a clever sleight of mind, a plot device for moving the story along? If so, toward what end? What if it turns out the self I think I am exists for no greater purpose than to trap lions in the Scottish highlands? Well then, the joke's on me.
Francois Truffaut, Hitchcock