“What if real life is actually a dream?”  is a favorite question of Modern philosophers and teenagers who want to sound deep. It’s a curious thought experiment, but in reality—that is, when we’re awake—we can all easily tell the difference between reality and a dream. But how? The answer is, I think, very simple, but also telling.

Thought experiments aside, we can tell reality from a dream because—to put it a little abstractly—reality contains so much more information than a dream does. Anything we care to focus on contains a wealth of detail which is immediately apparent to us. Whether it’s the threads in a blanket or the dust in the corner of the room or just the bumps in the paint on the drywall, reality has an inexhaustible amount of complexity and detail to it. And what’s more, it has this even in the parts we’re not focusing on. Our eyes take in a truly enormous amount of information that we don’t exactly notice and yet are aware of.

Dreams, by contrast, are very simple things. They do feel real while we are in them, but I think this comes from two primary causes. One is that we’re so caught up in the plot of our dream that we’re not paying enough attention to ask ourselves the simple question, “is this a dream?”

And I think that this is because dreams are natural to us. We often lose sight of this fact because dreams are involuntary and strange. But many things we do are involuntary, in the sense of sub-conscious; our breathing is most involuntary and our heartbeat always is. Our stomachs go on without our concentrating on them and our intestines wind our food through them whatever our conscious thoughts may be. Merely being involuntary does not make a thing unnatural. And since it is natural to us to dream, it is natural that we do not ordinarily try to escape our dreams. As with our other bodily functions, we ordinarily do what we’re supposed to do.

The other reason that dreams feel real to us is because our attention is so focused in a dream that we never consider the irrelevant details. If you ever try to call a dream back in your memory, though, you’ll notice that you can recall almost no detail in them—detail which was irrelevant at the time, I mean. The things in dreams only have properties where one is paying attention. The enormous amount of information we can see without paying attention to it is missing. This is also why they have a “dreamlike” quality to them—if we turn away then come back, they may not be the same because they stopped existing while we weren’t looking at them.

Dreams lack this stable, consistent, overwhelming amount of information in them precisely because they are our creations. We can’t create an amount of information so large that we can’t take it in.

And here we come to the fitting part: the difference in richness between reality and dreams shows what inadequate Gods we are. Our creations are insubstantial, inconsistent wisps. We can tell reality from a dream at a glance between it only takes one glance at reality to know that we couldn’t have created what we’re looking at.

(Note: This is a heavily revised version of a previous post, Discerning Reality From a Dream.)