With ‘Terminator 2: Judgment Day’, James Cameron essentially takes everything that worked about ‘The Terminator’ and asks: how much bigger can we make it?

The scale is enormous, the action sequences are more elaborate and the special effects raised the bar for what audiences thought was possible on screen. But what makes ‘Terminator 2’ such an intelligent sequel is that Cameron doesn’t simply repeat the original with more money. He reverses it.

Arnold Schwarzenegger returns as the Terminator, except this time he’s the good guy.

It’s a clever development that also reflects what had happened to Schwarzenegger’s screen persona in the intervening years. Films such as ‘Twins’ and ‘Kindergarten Cop’ had revealed a lighter, warmer and more heroic side to this enormous action star. Cameron takes advantage of that. The machine who was once the terrifying villain can now learn to care for humans.

And that becomes unexpectedly moving because ‘Terminator 2’ is, among many other things, a film about family and fatherhood.

John Connor has grown up without a stable father figure. The various men who have passed through Sarah Connor’s (Linda Hamilton) life haven’t provided one. Yet ironically it is a cyborg who becomes the most dependable male presence John has ever known.

The Terminator isn’t human, but he behaves more responsibly than many of the humans around him. He will protect John unconditionally. He won’t abandon him. He won’t betray him. His entire purpose is to ensure that this child comes to no harm.

There’s something both funny and rather poignant about John effectively teaching a killing machine how to become a father.

Cameron also does something here that recalls ‘Aliens’, as in both films he takes a genre traditionally dominated by men and places an extraordinarily formidable woman at its centre.

Sarah Connor has changed almost beyond recognition from the woman we met in the first film. Linda Hamilton has transformed her into a warrior, but she’s also something more interesting: a kind of prophet.

She has seen the apocalypse before it has happened. Sarah knows what humanity is going to do to itself, and nobody else wants to believe her. In that sense, she becomes almost a Cassandra figure, condemned for understanding the future too clearly.

There’s even something of the mother of the Messiah about her. John Connor is destined to become the leader who saves humanity, but Sarah is the person who has protected and prepared him for that destiny. More importantly, she begins to ask whether the supposedly inevitable future can actually be changed.

‘No fate but what we make’ becomes the philosophical heart of the film, in that beneath the motorbikes, explosions and gunfire, ‘Terminator 2’ is asking a serious question: can humanity be saved from itself?

The apocalypse hasn’t been caused by an alien invasion. It isn’t a natural disaster. We created it.

Human beings develop technology without adequately considering the consequences, eventually producing machines capable of making decisions for themselves. Those machines conclude that humanity is the problem.

Watching the film now, its anxieties about artificial intelligence are impossible to miss. Contemporary debates about increasingly capable AI systems, autonomous decision-making and the possibility of humans losing control of technologies they have created give Cameron’s story an immediacy that couldn’t have been entirely anticipated in 1991.

That’s the wonderful contradiction at the heart of ‘Terminator 2’: this is a technology movie that’s profoundly suspicious of technology.

Indeed, one of the most technologically groundbreaking films of its era is warning us about becoming intoxicated by technological progress.

It’s a clever form of self-criticism. The film dazzles us with what computers can do while simultaneously asking whether we have thought carefully enough about what computers should do.

The new Terminator is the perfect embodiment of that technological escalation.

Robert Patrick’s T-1000 is far more sophisticated than Schwarzenegger’s machine. Constructed from liquid metal, it can change its appearance and imitate other people. Shooting it achieves almost nothing. Blow a hole through it and the metal simply reforms.

So Cameron introduces a fascinating piece of twinning in that two machines arrive from the future. One has been programmed to kill John Connor; the other has been reprogrammed to save him. One represents technology turned against humanity, while the other represents the possibility that technology can still serve us.

Much of the film then becomes an extended chase.

Cars, motorbikes and trucks tear along highways and through concrete channels while the T-1000 pursues John with almost supernatural persistence. Every apparent victory is temporary because however much damage they inflict, the thing simply gets back up.

Yet Cameron understands that action only works when we’re invested in the people being chased.

That’s why the relationship between John and the Terminator matters so much. The machine gradually learns from the boy. John teaches him slang, humour and eventually something approaching morality. Most importantly, he teaches him that killing people isn’t necessarily the solution to every problem.

Meanwhile, Sarah is travelling in almost the opposite direction. The human being is becoming increasingly machine-like while the machine is becoming increasingly human.

Sarah becomes so obsessed with preventing Judgment Day that she is prepared to kill the man whose work will eventually lead to Skynet. At precisely the moment when the Terminator is learning the value of human life, Sarah risks losing sight of it.

That’s a remarkably clever reversal, and it leads back to the film’s central question. If the future isn’t predetermined, then preventing catastrophe isn’t simply about destroying technology. It depends upon human beings making different moral choices.

There is one moment towards the end, however, that has always struck me as odd.

The T-1000 tortures Sarah in an attempt to make her call out to John and lure him into danger. But we’ve already established that the T-1000 can imitate people perfectly. Why bother forcing Sarah to call him when it can simply become Sarah and call John itself?

And, indeed, that’s essentially what it subsequently does.

It’s a curious lapse in logic in a film that has otherwise thought remarkably carefully about the rules governing its machines. But it’s a relatively small complaint about a sequel that manages the rare achievement of expanding upon its predecessor without diminishing it.

Cameron gives us a bigger Terminator, a more spectacular Terminator and a technically revolutionary Terminator. But he also gives us a more thoughtful one.

At its heart, ‘Terminator 2’ is really about whether humanity possesses the wisdom to prevent itself from creating the machines that will destroy it. And the film’s most beautiful irony is that its most humane character may ultimately be the one who isn’t human at all, and from whom we need to learn a lesson or two.