At one level it’s a bit embarrassing to admit that I regularly watch movies based on comic books. I’m 56 and my youngest is 14, so it’s at least a semi-voluntary endeavor. Nonetheless, I grew up with subscriptions to DC Comics, the “Justice League of America,” “Classics Illustrated,” and an obscure favorite called “Metal Men.” These readings did not replace literature for my siblings and me; they supplemented it, and, with “Classics” especially, helped to pique interest in the real (and even unabridged) thing. It’s hard even now to describe the imaginative windows opened by just a handful of N.C. Wyeth illustrations in the editions we craved as children.

Thus, an invitation to watch a full-fledged Batman movie with today’s technological accomplishment is no bow to my teenage son, it’s irresistible. The new feature, The Dark Knight, is engrossing and visually spectacular. Unlike the comic books, however, it also has psychological depth and is almost unremittingly dark. It is good v. evil, certainly, but it is a troubled good confronting, in the character of the calculating Joker played by the late Heath Ledger, an almost-explicable evil.

The intense scenes of the Joker wielding knives in the face of his victims are stomach-churning to watch (at least one hopes that audiences have not become used to scenes like this that, in Roman Polanski’s 1970’s film noir Chinatown, became an iconic image of sadistic criminality), but it is during these scenes that the character explicates his personal history. He is the tormented product, he seems to imply, of his father’s wanton cruelty to his mother, just as much as Batman, played by Christian Bale, is the product of his father’s heroic effort to save his mother. Role reversals abound in the movie, and the public’s need for heroes it can both treasure and revile supplies the broad dramatic tension, but good fathers clearly matter.

Among the twisted ethical dilemmas the Joker poses to Gotham City involves two ferry boats full of passengers who are challenged to a potentially mutually fatal decision. One boat is full of criminals, the other ordinary citizens, so it is not a “Sophie’s Choice” that is presented. The scene is played out to an extraordinary conclusion. In the murky moral swamp into which Gotham City has sunk, this depiction of “lifeboat ethics” leaves plenty of room for thought. The Dark Knight is overlong and the violence exceeds its prequel, Batman Begins, and there are instances of implied sexuality and some language.

Finally, the film redefines the Batcycle just as Batman Begins redefined the Batmobile. At least a few things in Gotham City have gotten definite upgrades. Now if only my mother hadn’t thrown out a half million dollars’ worth of comics . . .