In preparation for the new live-action Ghost in the Shell movie, I recently returned to the 1995 anime film on which it’s based, and I couldn’t help but think of two things: The Matrix, and philosopher Daniel Dennett.

The link to The Matrix is obvious enough. Before making that movie, the Wachowskis showed Ghost in the Shell to producer Joel Silver as an example of what they wanted to accomplish with their non-animated action sequences. It’s not an adaptation, but The Matrix ended up borrowing heavily from both the structure and visuals of Ghost in the Shell.

As for Dennett, the movie dwells on many of the same questions and ideas about the nature of consciousness with which Dennett, a philosopher and cognitive scientist at Tufts University, has spent the better part of his career engaging. As a recent New Yorker profile of Dennett notes, he believes that consciousness is “something like the product of multiple, layered computer programs running on the hardware of the brain.” It’s an evolutionary process, purely physical in nature, in which sensory information and other biological functions combine and grow correspondingly more complex over time. There’s no mystery — just complexity.

The anime Ghost in the Shell finishes with a protracted shootout against a giant robot tank that looks like a spider — but the true climax is a lengthy monologue in which the villain, a sentient computer program, explains how he unexpectedly gained self-awareness, and laments the lack of basic life systems like death and reproduction. He finishes the speech by asking the movie’s protagonist, the cybernetically enhanced security officer Major Kusanagi, to merge with him, allowing for an evolutionary procreation. It’s a Dennett-esque foray into both the emergence of the self and its evolutionary perpetuation.

These are the sorts of consciousness-expanding questions that have animated the Ghost in the Shell franchise for more than two decades. The world of Ghost in the Shell is part futuristic action movie and part philosophy lecture, in which artfully constructed animated action sequences serve as vehicles for investigations into the nature of consciousness. It’s a showcase for what top-notch animation can do — one that the new movie never quite manages to match.

By positing a world in which people merge with machines, Ghost in the Shell examines what makes us fundamentally human

The Ghost in the Shell franchise began as a Japanese manga series in the late 1980s, but it was the 1995 movie that built its international reputation.

The film arrived at a time when anime was gaining global reach, and it highlighted the form’s strengths: richly detailed art, high-concept sci-fi world building, stunningly executed action sequences, and a willingness to deal in both adult themes and content.

For many, including me, Ghost in the Shell was a gateway to the wider world of Japanese animation, one that blended the appeal of comic books, movies, and science fiction — in particular, the sort of noir-tinged cyberpunk that Western writers like William Gibson had popularized in the 1980s.

The film introduced the characters and ideas that would become the foundation for the franchise. Those characters included the franchise’s protagonist, Major Kusanagi, a human-machine hybrid whose construction is shown during the film’s opening credits, and her colleagues Batou, a gruff, tough cyborg with enhanced eyes and a shock of white hair, and Togusa, a newbie officer who is probably the closest thing the movie offers to an audience surrogate. They all work for Section 9, a shadowy government security agency run by the aging Chief Aramaki, another character who would recur throughout the series. The story follows Section 9’s pursuit of a mysterious hacker known as the Puppet Master who, in a world of computer-enhanced individuals, can hack humans as well as machines.

Director Mamoru Oshii wanted a movie that portrayed the “influence and power of computers” by looking at how that influence and power might evolve over time, and the film posits a near future in which humans have begun to merge with machines. Limbs are upgraded with weaponry and other special functions; eyes are replaced with powerful computer-enhanced sensors; minds and memories are expanded via external storage technology.

The inevitable question that arises from all this, of course, is how much artificial enhancement and replacement can a person undergo and still remain fundamentally human?

That’s where the concept of the “ghost” comes in. A ghost is a person’s deep self, his or her essence, which remains intact even as one’s physical body becomes more and more integrated with computers and machines. The name is a reference to philosopher Arthur Koestler’s 1967 book The Ghost in the Machine, a treatise on the nature of consciousness whose title was borrowed from another philosopher, Gilbert Ryle, who coined the phrase to describe the notion of consciousness as somehow apart and separate from biological processes.

Koestler’s book took up the notion that humanity’s existence might have been a mistake, an evolutionary error, and dealt with humanity’s propensity to violence and awareness of the inevitability of death — all ideas that would come into play, in various ways, throughout Ghost in the Shell’s story.

This thematic richness would come to define the franchise — and occasionally weigh it down, especially under Oshii. His 2004 sequel, Ghost in the Shell 2: Innocence, is, in theory, another action-noir in which Batou and Togusa, now partners, investigate a series of murders involving robotic geishas that have been implanted with humanlike artificial intelligence.

If anything, the Ghost in the Shell sequel is even more densely packed with philosophical references than the original: The film’s questioning, ponderous dialogue name-checks French philosopher René Descartes and John Milton, among others, and includes scenes in which robot replicas of the two detectives spout lines like, “The 15th century man-as-machine theory has been resurrected by cyberbrains.”

In an action scene near the end, the script winks at its own proclivities when Batou, facing an army of killer geisha-bots, grumbles, “Look, this ain’t the time to get philosophical — I’m running low on ammo here.” In the world of Ghost in the Shell, though, it’s always time to get philosophical.

The sprawling Ghost in the Shell franchise is linked by a commitment to science fiction world building and philosophical inquiry

It’s not necessary to catch every academic reference to enjoy the Ghost in the Shell series. The action sequences are reliably inventive and thrillingly staged, with blocking that is better choreographed than many live-action films. The animation by Production IG, one of Japan’s most accomplished animation houses (if you’ve seen the animated sequence from Kill Bill, you’ve seen their work), is consistently stunning, particularly in the way it blends environmental details. New Port City, the fictional Asian city where the series is set, is based partially on Hong Kong, and with its mix of grime and tech, modern mega-architecture, and busy street markets, it has the feel of a real place. It’s an aging metropolis built up in layers, over time, the urban counterpart to Dennett’s theory of consciousness.

The technology, too, is intricate and fascinating: Robotically enhanced bodies expand and reshape themselves, revealing fingers made for ultra-fast typing and eyes that jack into digital sensor arrays. The design work is busy and functional, almost industrial at times, as if designed for use rather than stylishness. Watching the series today, some of the choices can come across as a bit strange, in particular the reliance on bundles of wires for connectivity. But that’s part of the series’ charm: Even in more recent incarnations, it’s a vision of a future that is, in some sense, a perpetual extension of the technology of 1995.

Those later incarnations include the TV series Ghost in the Shell: Stand Alone Complex, which ran for two seasons starting in 2002. Written and directed by Kenji Kamiyama, the show was an extension of the first film that also featured the Major, Batou, Togusa, and Aramaki. Although it was more of a traditional sci-fi action procedural than the film that inspired it, it nonetheless dealt in similar concepts and questions about computer networks, identity, consciousness, and reality. The first season sent the team on the trail of another mysterious hacker, the Laughing Man, while the second pitted them against a terrorist group called the Individual Eleven, which spread a virus through the posting of a fake terrorist manifesto. (Both seasons were also recut and re-edited into feature-length movies titled The Laughing Man and Individual Eleven, respectively, that focused more narrowly on the season-long plot arcs.)

More recently, the franchise has been essentially rebooted in a series dubbed Ghost in the Shell: Arise, a sequence of five original video animations (essentially hour-long mini movies) that were later recut into a 10-episode TV series, and which connected with the feature-length 2015 film Ghost in the Shell: The New Movie. Arise takes place in an alternate continuity but has many of the same elements as the rest of the franchise, including the main cast of characters (albeit with new designs) and animation by Production IG.

What links all the various iterations is a commitment to science fiction world building and philosophical inquiry. At every turn, the series offers a reminder that animation can do more than comedy and kid stuff — the realm in which it is most often found in the United States — and that at its best, it’s also capable of ideas and action, drama and intellectual engagement, mind-blowing imagery and stories to match.

Sadly, the big-budget, live-action reboot doesn’t live up to its animated predecessors. Sure, it’s a visual marvel, often faithfully replicating key scenes and images from the original film, and sure, there’s still a lot of talk about ghosts and souls and what it means to be a human. But the characters themselves are all empty husks — there’s not a single identifiable personality in the film — and both the visuals and the dialogue lack the deeper context of the original. The search for the idea of a soul has been streamlined and Westernized into a simple quest for individual identity and memory.

The result is a movie that’s all borrowed parts, with no depth or connection. The layers never quite come together to form something more. It wants to be a movie about the search for consciousness, but, unlike its source material, it doesn’t have a soul.