The scariest thing in the world is uncertainty.

If that's true, that might explain why ghost movies are scarier than zombie movies or vampire movies. At least with zombies and vampires we understand their motives and how to deal with them. But ghosts appear to us when we're vulnerable and alone, and they leave no evidence we can share with a friend. An encounter with a zombie or vampire is invigorating, but seeing a ghost invokes existential fears and self-doubt.

Among ghost movies, The Haunting (the 1963 version, not the remake) stands (severed) head and shoulders above the rest. Based on Shirley Jackson's The Haunting of Hill House, it's practically a recipe for what makes a good ghost story.

What makes a good ghost story is plausible deniability. A skeptic in the cast of characters can rationally explain that just because a spot in the hallway is cold, doesn't mean that a ghost just passed through. It's just as likely that the cold spot is near a leaky seal without insulation. What makes a good ghost story is the possibility that your "ghost" is actually a scam, a mental breakdown, or a simple case of Mulderitis ("I want to believe").

What makes a good ghost story is shades of gray. If the person who hears something terrifying in the night is the character who is already a little unstable, then the other characters and the audience won't know whether it was the supernatural, an active imagination, or stress-induced madness (another frightening possibility).

What makes a good ghost story is a very long, steady buildup of tension. It's easy for the skeptic to explain the cold spot, but what about the bleeding statue, or the breathing door? A long setup of creepy but explainable phenomena also gets you into the same paranoid frame of mind as the characters so that when they jump, you jump. (What makes a good ghost story is a person in the cast of characters who is jumpy and who screams.)

In The Haunting, four characters converge on Hill House, a mansion with a reputation for being haunted. The man who arranges the stay is Dr. Markway (Richard Johnson), a scientist interested in the paranormal. He hopes to become the Newton of the netherworld, the scientist who discovers the natural laws of the supernatural. He invited a handful of students who scored high on paranormal tests. Only two agreed to come: Theodora (Claire Bloom), a bold, aggressive, cat of a woman; and Nell (Julie Harris), a mousey woman who until two weeks ago had never lived out from under the thumb of her overbearing mother (may she rest in peace). The smart-alecky nephew of the current owner of Hill House Luke Sanderson (Russ Tamblyn) is asked to chaperone.

The haunting in The Haunting starts laughably small. Dr. Markway shows everyone the library with the rickety spiral staircase, the greenhouse with the unhappy statues of the family, and the house's notorious cold spot. Luke makes light of all the "scary" stories, which aggravates the overly sensitive Nell. And so it goes for the first half-hour of the film.

The first turning point happens at night, to Nell, and we're not quite sure whether it's because of the stress of her mother's death, the reputation of the house, an actual ghost, or some combination thereof. From there, things get creepier, the characters begin to bicker, relationships get strained, nerves get frayed, and the house's story becomes more vivid and plausible. When a new scoffer moves into the gothically decorated nursery ("Suffer the Children" adorns the wallpaper), you can hardly bear to watch.

Whether the movie is ultimately about a genuinely haunted house or just four jumpy people doesn't matter, so I won't tell you which it is. Instead let me leave you with a list of Halloween recommendations. These are movies, -- some truly scary, some merely tense -- that won't tell you right away, if ever, whether there's actually something to be afraid of.