A few days ago we made passing mention of the Oxford philosopher of science Nick Bostrom’s Simulation Argument, which makes the claim that we are probably living in some sort of Matrix-like computer program. This dismal notion, which we looked at a bit more closely back in May, was also the subject of a brief article in last week’s New York Times.
There are several worthwhile objections to Bostrom’s idea. One serious weakness, and the one that I’ve mentioned at every turn, is that the simulation argument rests on the assumption that actual consciousness can arise in any system that is running a suitable program. It is easy to see the appeal of this idea, given that our brains do seem to be in both the information-processing and consciousness-producing business, but the fact is that we don’t even have a coherent description of what consciouness is, let alone any solid knowledge of what, exactly, it is about our brains that enables them to produce it. While it may, perhaps, turn out to be that the right sort of information-processing is indeed all that’s needed, and that any similar program running on any suitable platform can manage the trick, we certainly don’t have any account of why that should be, or in virtue of what, in particular, one program might bring about a conscious mind while others wouldn’t. The brain is not only a hugely parallel information-processing machine, but also an enormously complex physical object, and it seems likely to me (here I agree with John Searle) that it is in virtue of some of its physical properties, as well as its abstract informational content, that the brain gives us our subjective awareness.
I also think Bostrom is underplaying the difference between simulations and reality: you can simulate a storm in a computer model, but the simulated rain makes nothing wet. You might argue that the simulated rain floods the simulated roads, and that the simulated wind knocks down the simulated trees, but Bostrom is flattening the hierarchy here: he is talking about actual consciousness — our own, in fact, which is as real as it gets! — arising inside his putative simulation. I see no reason to believe this is possible.
Another problem, of a different sort, is that Bostrom’s argument seems, for now at least, quite untestable and unfalsifiable, and therefore lies, arguably, beyond the realm of science. For that reason, quite a few people seem to be annoyed that the Times would have featured it in last Tuesday’s science section (on the first page, no less).
One who seems awfully vexed is Columbia mathematician, particle physicist, and author Peter Woit, who in his latest book Not Even Wrong: The Failure of String Theory And the Search for Unity in Physical Law joins Lee Smolin in criticizing string theory as an untestable, and therefore scientifically unproductive, waste of some of today’s brightest minds. Dr. Woit has a blog by the same name, and in it I found a lively thread, 50 comments long, addressing Bostrom’s argument, the article in the Times, what is and isn’t science, and a number of other things besides. This looks like a good, grumpy site of the sort I enjoy; readers are invited to take a look also. Onto the sidebar it goes.