Christian Slater stars in “My Own Worst Enemy” (9 p.m., NBC) as two very different versions of the same man. Edward (Slater) is a super-spy and a trained killer. Henry (Slater) works in a corporate office and goes home to a nice wife (Madchen Amick) and two adorable children.

Twenty years back, the scheming Edward conspired with spymaster Mavis (Alfre Woodard) to create Henry’s character by implanting memories and sensations in a part of Edward’s brain. It’s a little like running both PC and Apple operating systems on the same hard drive. It’s possible, but why bother?

Somewhere along the line, the psychological firewall separating Edward and Henry breaks down, creating real confusion for them (and us). Given this elaborate setup, I’m still not entirely sure why the Henry “creation” was or is necessary to Edward’s work. But you can rest assured that Henry, fake memories and all, will fight to survive.

“Enemy” is the latest in a series of drama/fantasies that blur the line between fantasy and psychosis. Is television suffering a collective nervous breakdown?

On a surprising number of shows, characters experience disturbing symptoms, including shared delusions (“Heroes”); divine visions (“Eli Stone”); dangerous revelations (“Chuck”); godlike powers (“Pushing Daisies”); communication with the dead (“Ghost Whisperer,” “Medium”); amnesia (“Samantha Who?”); diabolical forces (“Supernatural,” “Reaper”); insight tempered by madness/depression/multiple disorders (“Monk,” “Fringe,” “House,” “Lost”); disturbing clairvoyance (“True Blood”); and sociopathic homicidal urges (“Dexter”). And that’s the short list.

Just what does all of this madness and morbidity say about our culture?

“Enemy” also presents a reverse spin on the old Alfred Hitchcock formula – the average man facing extraordinary danger. In “North by Northwest,” an advertising executive (Cary Grant) held his own against evil spies. In both “Enemy” and “Chuck,” the main character rises to the occasion only because his brain has been rewired by superior spymasters. In the aftermath of World War II and its victorious army of citizen soldiers, the unsentimental Hitchcock could celebrate a faith in the common man. Today, the ordinary Joe, or Henry, is portrayed more like a programmed pawn than a flesh-and-blood hero.

Tonight’s other highlights

¢ Sarah’s ex return and joins her on an awkward assignment on “Chuck” (7 p.m., NBC).

¢ The Dodgers and Phillies meet in Game 4 of the NLCS (8 p.m., Fox).

¢ Ray Liotta lends his voice to a new “SpongeBob SquarePants” (7 p.m., Nickelodeon).

¢ Matt finds a kindred spirit in Iraq on “Little People, Big World” (7 p.m., TLC).

¢ Claire hunts down a potent escapee on “Heroes” (8 p.m., NBC).

¢ “American Experience” (8 p.m., PBS, check local listings) profiles Richard Nixon.

¢ “Secrets of Body Language” (8 p.m., History) explores nonverbal communication.

¢ The documentary “Section 60: Arlington National Cemetery” (8 p.m., HBO) visits the area where the funerals for the most recent combat fatalities take place.

¢ Cybill Shepherd guest stars on the second-season premiere of “Samantha Who?” (8:30 p.m., ABC).

¢ An old flame hires Alan on “Boston Legal” (9 p.m., ABC).

¢ Ted Koppel presents “The Last Lynching” (9 p.m., Discovery), a look at domestic racial terrorism.