Think you understand Inception? Meet the philosophy professor who says you’re wrong

The ending of Inception, Christopher Nolan’s headache-inducing sci-fi classic, has always pleasurably tormented its fans. The 2010 film follows a group of thieves who use experimental technology to infiltrate and steal from people’s subconscious minds, but in doing so risk losing touch with reality.

In the closing scene, the group’s anguished leader, Dom Cobb, played by Leonardo DiCaprio, is at last back in the real world with his children. But is the moment real, or just the fantasy of a man who has lost everything? Should we sigh contentedly through the closing credits, or weep?

The final shot – a slow zoom in on Cobb’s spinning top – promises the answer. According to the film’s rules, the top will eventually overbalance if we’re in the real world, but spin indefinitely in a dream. At the end, we cut to black just as the top seems on the point of falling over – but does it? We’ll never know. Nolan’s cinematic achievement is to have loaded an apparently trivial ambiguity with such emotional weight.

Since the release of the film, which has returned to cinemas this week, the director has always maintained that the answer doesn’t matter. He suggests that the viewer take their cue from Cobb himself, who turns his back on the top to run forward and embrace his children. What do insignificant distinctions like dreams and reality matter when happiness is at stake?

But perhaps we’ve just been asking the wrong question. Stephen Mulhall, professor of philosophy at the University of Oxford, certainly thinks so. His work on the philosophy of film, and Inception in particular, calls into question our assumptions about the film and its ending.

The problem with the ending, Mulhall tells me by phone from Oxford, begins with the function of the spinning top.

“What I think a lot of viewers don’t take on board is that it’s not meant to tell you the difference between dream and reality – it’s meant to tell you whether or not you’re in someone else’s dream.”

In Inception, most of the characters have a personal totem of some kind for this purpose. No one but the owner knows its distinctive property, which means that no one else’s subconscious will be able reproduce it accurately. It gives the owner an instant reality-check. If your totem is misbehaving – in the case of Cobb’s spinning top, by not falling over – then you know you’re in someone else’s dream.

But, Mulhall points out, “one of the weird things about the spinning-top totem is that it’s not at all obvious how it’s going to perform that function in the first place.”

“What’s supposed to reveal the difference [between dream and reality] is whether or not it keeps spinning endlessly.” (This is implied, although never explicitly stated, in several previous scenes.)

“But anybody with half a brain who constructs a dream they want to fool you into thinking is reality would not put an endlessly spinning top in it. They’d know enough about the basic behaviour of physical objects to realise that that’s one thing it definitely wouldn’t do.”

This is only Mulhall’s first problem with a popular understanding of the ending. “It’s fairly clear that the worry is not whether Cobb is in the real world or someone else’s dream,” he says. By this point, no other character has any motivation to trap him in their subconscious.

The question is whether he is in the real world or his own dream – “a kind of wish-fulfilment fantasy that he’s come up with because he misses his children so much”.

If it is Cobb’s own dream, then the top would fall over anyway, since his subconscious has as much access to its distinctive property as his conscious mind. It would be useless as a signifier of reality.

Mulhall’s observations seem to wreck both the pleasure and the significance of the ending. The final shot’s teasing refusal to tell us what happens is no longer any fun because we already know the answer – the top must fall – and this knowledge is rendered pointless because it has no bearing on the issue we care about, namely whether Cobb is in the real world or his own private Disneyland.

Luckily for Inception fans, having torn the film’s value to shreds, Mulhall now proceeds to put it back together. He proposes two possible explanations: either Nolan has “completely cocked it up” or “the significance of the ending has to be understood in some other way”.

He considers the first possibility “wildly implausible”. For what it’s worth, I disagree – Christopher Nolan does not have a PhD in philosophy – but most critics, including Mulhall, would say it doesn’t matter all that much. Once created, a piece of art exists beyond the reach of the artist; ultimately, it means what it means, irrespective of what they intended. Funnily enough, this is an idea that Nolan has discussed himself.

Either way, it’s more interesting to consider the second possibility. For Mulhall, any new understanding requires a fundamental shift in the philosophical concerns of the film.

The questions apparently posed by the ending, personified in the character of Cobb, are those of the traditional philosophical sceptic: “Is this world real? How can I be sure I’m not dreaming?”

But with the recognition that Cobb’s totem has no bearing on whether or not he is dreaming, that it can only tell him (and the viewer) if he is in someone else’s dream, comes a different kind of scepticism. What is in doubt is no longer the existence of the rest of the world and all the other people in it – for someone to produce a dream, they must exist – but the sceptic himself and his own independent mind.

“The reality of other people in Inception is absolutely undeniable,” says Mulhall. “It’s a vision of the world in which other people’s minds constantly invade your own.” Stealing intellectual property via dreams is, after all, how most of the characters pay the bills.

In light of this, the awful possibility apparently embedded in the ending – that Cobb’s children are not real, that he has conjured up a fantasy version of them in order to avoid facing a reality in which they aren’t there – no longer feels like the film’s genuine anxiety.

“The real worry of Inception is not the reality of other people, it’s the reality of your own mind.”

The clue is in the title: “Inception” literally means origin or starting point. Do you really know where your ideas come from? “The subject’s mind can always chase the genesis of the idea,” proclaims Arthur (Joseph Gordon-Levitt), Cobb’s criminal partner, in an early scene. “True inspiration is impossible to fake.”

“That’s not true,” Cobb retorts.

Such a worry, Mulhall points out, has a far more direct bearing on ordinary life than the more traditional flavour of scepticism.

“The idea that the contents of our own minds derive from other people is absolutely fundamental to the human condition. Where do our ideas come from? They come from books we read, films we watch, politicians we listen to.

“But that’s a very uncomfortable thought. It shows that our minds aren’t our sovereign private property, but are in fact dependent on, and vulnerable to, the minds of others.”

This changes the meaning of the ending but not its emotional impact. The tension that builds as we watch the spinning-top wobble – a tension we also owe to our investment in Cobb and his happiness – no longer corresponds to a big, existential fear about the nature of reality, but something smaller, more precise, more familiar from everyday life.

It is what the late critic Harold Bloom called “the anxiety of influence” – the fear that our best ideas are not our own. Perhaps it’s Christopher Nolan’s biggest personal preoccupation, or perhaps he put the idea there for Mulhall to find without even realising he was doing it. Perhaps his mind is not entirely his own. Perhaps yours isn’t either.