Less than unplugged: the simulation argument
Inception and The Matrix are films that tell compelling stories about people living within simulated worlds. In the case of Inception, the simulations are created in the dreams of corporate spies known as ‘Extractors’; in The Matrix, the simulated world is an illusion created by machines as a means of enslaving humanity. Both films explore the issue of how someone could possibly know if they were in a simulation, and the feeling we get is that perhaps we wouldn’t.
Whilst people might be prepared to acknowledge the power of such an illusion for the characters in a film, presumably rather fewer would accept that there is a genuine chance they are in a simulation right now. One barrier to taking this notion seriously is the fact that there is currently no technology capable of performing such simulations. But that is not to say this technology will always be beyond us. It is reasonable to suppose that if humans survive into the far future our technology will be more than adequate. It is an open question as to how many civilisations in the universe are already at such an advanced stage of technology. And there’s the rub: the evolution of intelligent organisms capable of forming civilisations is probably exceedingly rare, but amongst the complex civilisations that do exist, the simulation of intelligent agents is potentially much less rare. Furthermore, if we assume that a civilisation capable of simulating a universe is capable of simulating many universes, there would appear to be the very real possibility that there are more simulated conscious agents in existence than there are real ones; it might be more likely that we are simulated than real.
The notion of being a simulated entity is admittedly rather unappealing, but perhaps it’s not the worst case scenario. Might it not also be possible for sufficiently rich simulations to run simulations of their own? In other words, there is presumably a chance that, far from being real, we are merely second order simulations, simulated within a simulated world! Perhaps we are at the mercy of several higher-order coffee cups, any one of which could spill and destroy one of the machines that computes our reality.
My feelings towards the simulation argument are the same as to the Drake equation. Everything sounds plausible, but there’s just nothing to hang your hat on, no concrete numbers to give you an idea one way or another as to which reality is most likely. Having said that, it does a marvellous job of moving simulation from the fringe of physics and philosophy to the heart of many debates. The advantage of entertaining the idea is that we are less likely to overlook explanations that are outside of the normal physicalist perspective. Starting with the assumption that we are simulated might be a fruitful line of inquiry whether that assumption is correct or not.
Whilst built on foundations stretching back to Descartes’ Meditations (1641), the modern simulation argument owes everything to the work of the Philosopher Nick Bostrom, in particular his paper from 2003. For more, listen to this excellent interview with Bostrom or visit his curated set of links on the subject at his simulation argument website.
Bostrom, N. (2003). Are you living in a computer simulation. Philosophical Quarterly, 53(211), 243-255.
Descartes, R. (1641). Meditations on First Philosophy – Translated by Cottingham, J. (1993). Cambridge University Press.