Like works of art, machines are not alive. Appliances, gadgets and tools only contain as much heart, or the appearance thereof, as human beings put into them.

Lonely robot WALL-E (center left) falls in love with robot probe EVE (center right) in Pixar’s smart new blockbuster.

A robot that contains an inexplicable soul stars in the title role of WALL-E, the latest film from Pixar, which has inspired an assembly line of computer-animated splendor. WALL-E the robot, not unlike all of Pixar’s movies, is an efficient, state-of-the-art construct that’s somehow all heart on the inside. Open up WALL-E’s hood and you’d no doubt see a big, beating valentine like the X-ray at the end of the How the Grinch Stole Christmas cartoon.

WALL-E, written and directed by Finding Nemo’s Andrew Stanton, never explains how a “Waste Allocation Load Lifter ­- Earth class” attained a feeling personality. As we follow WALL-E’s sad-sack exploits in the 28th century and find him to be as engaging as any silent film star, including Charlie Chaplin’s Little Tramp, WALL-E’s heart and soul can be taken as a given.

Stanton neatly divides WALL-E into two parts with dramatically different color schemes and emotional textures. The first half-hour counts as, in effect, the I Am Legend section, as WALL-E goes about his business as the last sentient entity on Earth. With almost photorealistic clarity, the first section’s dusty, sun-baked earth tones suggest the planet has become a ghost town.

WALL-E resembles a trash compactor on treads with binoculars for eyes. He spends much of his time on his “day job,” crushing junk into cubes, which he then arranges into artful architecture. In his spare time, WALL-E collects enigmatic human artifacts such as sporks or bubble wrap, not to mention spare parts from other WALL-E units that lacked the spark of life.

Like most of the film’s robotic characters, WALL-E’s dialogue consists of few words and a lot of mechanical beeps, provided by sound designer Ben Burtt, who gave R2-D2 his voice in the Star Wars movies. The quirky robot’s thoughts, however, prove perfectly transparent. We can tell he’s lonely for love from the way he repeatedly watches a hand-holding scene from a degraded videotape of Hello, Dolly!

Companionship comes from the heavens, sort of, when a probe called EVE lands from space to assess whether Earth can sustain life again. EVE displays a personal touch beyond her directive, too. When alone, the elegant, capsule-shaped robot flies in exuberant circles as if to loosen up and later, she blows up a fleet of beached ships, frustrated at her mission’s apparent failure. WALL-E gradually gains her attention and affection, and though she’s clearly a much more advanced model, since Knocked Up matched up Katherine Heigl and Seth Rogen, EVE and WALL-E can be a credible pair, too.

When EVE’s ride returns her to outer space, WALL-E clings to its exterior to stay close to his true love. His trek through the stars includes brief, mind-blowing displays such as millions of dead satellites encircling the Earth, and WALL-E tracing his fingers in the ring around Saturn. Eventually they reach the Axiom, a giant space vessel that contains the whole of humankind and resembles a luxury cruise ship, complete with a lido deck.

From here, WALL-E’s visuals turn to polished pastels as the themes echo the cult film Idiocracy. Seven centuries of pampered luxury aboard the Axiom has turned humanity into a race of cheerful, complacent couch potatoes, carried around on high-tech Barcaloungers, while distracted by virtual interfaces and innovations like “Cupcake in a Cup!” A panoramic shot shows the passengers ferried beneath a sign that announces “Welcome to Economy.”

The word “Economy” doesn’t just refer to a ship’s Economy Class — we can only imagine the luxury of the Axiom’s First Class accommodations — but implies a metaphor for corporate-driven mass consumption. A Wal-Mart-style company called Buy & Large runs the ship and implicitly produced the litter that overwhelmed the Earth in the first place (although one has to wonder how much merchandise from Cars and other Pixar films filled the global junkyard).

As WALL-E struggles to reunite with EVE, his gallant quest uncovers a conspiracy that has kept mankind pampered and ignorant for centuries. WALL-E befriends a band of malfunctioning robots, including an automatic beach umbrella and a tennis-ball shooter, who become a lovable bunch of misfits comparable to Toy Story’s mutant playthings. Meanwhile, the ship’s blobby, indolent captain (Curb Your Enthusiasm’s Fred Garlin, the film’s primary voice actor) resolves to think for himself, take charge and walk on his own two feet.

With remarkable images and incisive satire, WALL-E represents science fiction at its best. Amid its sweet moments of robotic romance and physical comedy timed down to the millisecond, WALL-E offers an unusually tart message compared with the more comforting content of Pixar’s other films. Stanton holds up a mirror to his audience’s most lazy, indulgent impulses, and some may not thank him for it.

Fortunately, WALL-E’s plucky robot hero sets a good example. On board the Axiom, his chance encounters nudge both people and artificial intelligences out of their deadening routines. Two passengers discover the joys of real activity and companionship, while robots transcend their programming. It’s ironic that a robot should remind people how to be human, but Pixar’s CGI classics have always demonstrated a similar message. The studio’s flair for computer animation unerringly finds the soul of a new machine.