It goes without saying that this post contains ‘spoilers’ for Inception.

After I’d first seen Inception, I thought that it was good, but not brilliant. Roughly speaking, I’d taken it at face value. I’d taken it as a sci-fi action movie with a nice idea at its core about ‘dreams within dreams’. There were a few plot points it had glossed over, but then every action movie does that. I remember thinking that I’d actually expected it to be cleverer, given all the hype I’d heard. Sure, the idea of a dream within a dream is quite a cool one, but it isn’t a complicated one and the movie itself wasn’t difficult to follow, as a lot of complex thrillers are.

Slowly, however, the ideas began working on me.

What I’d thought was an ultimately harmless sci-fi action movie about dreams within dreams was perhaps really an obsessive psychological thriller about shared dreams (which is much subtler than just dreams within dreams (I also use the term both in the fictional sense in which it is used in the film and in the looser sense of ‘common ambitions’ (such as growing old together))).

My big objective in these posts is not to unearth some hidden meaning in the film, and then claim that it is the real truth but merely to help demonstrate the conceptual richness of the film and attempt to use it as an excuse to mention some very influential mathematical ideas.

In this post we’ll introduce the search for more interesting interpretations of the film by first getting down to the essence of the most basic interpretation. I will discuss the important idea of how one can tell that one is in a dream. Then I’ll move on to talking about actual issues with the plot of the film. In the next post, we’ll start on the mathematics, leaving Inception behind while we introduce the relevant ideas from the work of Kurt Gödel. Hopefully then we’ll be able to have a little discussion at the end about what on earth I am going on about.

What you know you know

I think that one way of looking at the aforementioned ‘face-value’ reading of the film is that it relies on the assumption that the combined knowledge of shared dreaming possessed by Cobb and his team is more or less all there is to know about shared dreaming and moreover, the viewer really is given all of the vital information about shared dreaming. Then, the small unexplained bits of the plot are more or less genuine plot holes but we don’t really mind because it’s a darn good action movie anyway. That’s fine and most people who don’t spend any more time thinking about the film than this will probably still agree that it makes a good action movie.

However, we all know that the fun starts when you dig a bit deeper. Let’s think about how well the film stands up to wilder interpretations.

We are led to ask, “What if Cobb doesn’t know as much as he thinks he knows about shared dreaming?” For example, the face-value reading takes Cobb’s side of the argument in the row he has with Mal (shown in flashback) about whether or not they are both still dreaming after their long experience in limbo. This new skeptical approach isn’t so sure. Similarly, when Cobb, Nash and Arthur wake up on the train, near the beginning of the film, you are led, naturally, to believe that you are seeing reality and not a dream, because, again, Cobb believes that it is reality.

I really had to see it twice because it wasn’t until the very final shot of the film that I realised how much mileage there was in the idea that Cobb that doesn’t know as much as he thinks he does.

Believing It When You Dream It

In the previous section we begun to see how we might arrive at new interpretations of the movie by questioning what we think we know. The relevant manifestation of this question in Inception is that of how and when characters can know that they are in a dream.  Let’s start by throwing all the totem mumbo-jumbo out of the window and just think rationally about this for a moment. The following seems like a reasonable starting point: Namely that someone can know that they are in a dream when they become consciously aware of something that cannot occur in reality (or is, at the very least, highly improbable). Examples from the film include implausible shifts in weather, structures collapsing, structures changing, gravity vanishing, paradoxical architecture etc. If I become consciously aware of such an inconsistency in the world around me, then I can say “Aha! I must be in a dream!”.

This is relevant because substantial elements of the drama of the film come from people believing that the dream they are in is, in fact, reality.

So, even if the dream genuinely does include something like paradoxical architecture, successful extraction/inception requires the dream to be sufficiently rich so as to be able to convince a specific dreamer (usually the subject, e.g. Fischer, say) that what he or she sees is reality, and therefore consistent. So, crucially, it needs to include enough so as to have the power to convince you of its own consistency.  If you’ve seen the film then this is actually quite an obvious statement, but do bear with me.


It’s all well and good assuming the Cobb doesn’t know as much as he thinks he knows and subsequently hunting for an original take on the events of the film but after going over things again, seeing the film again and reading about the film, one might began to notice some issues. Indeed almost anyone who’s thought about it would agree that there are some parts which seem to need much more explanation, some parts which, on reflection, seem implausible (even within the fiction of the movie, I mean) and potentially some genuine plot holes (I won’t go into details here; one need only browse any one of the many Inception discussion forums online in order to get an idea of the type of unanswered questions/inconsistencies I am talking about).

However, the conclusion of the previous section applies to the movie as a whole. Even if on some level the film does contain genuine inconsistencies, it needs to include enough so as to convince the viewer of its own consistency. If I am convinced (as I was the first time I saw the movie) then I will dismiss the minor plot issues that I notice or explain them away within the fiction of the movie (“Oh maybe that’s just how limbo works…” etc.). The result analogous to the subject of a dream not knowing he or she is in a dream is the viewer buying in to the fictional world of the movie.

So, the film itself, much like the dreams it portrays both a) Has inconsistencies and yet b) Needs to be able to convince of its own consistency.

Onwards to Gödel in the next post.