Are We Real? (Pt. I)

I have occasionally written (see most recently here and here) on the fascinating notion that the universe we live in is actually not "real" but is rather a computer simulation designed by some intelligent creatures living in a different world altogether. This theory has been popularized, perhaps most notably, by philosopher Nick Bostrom.

I find the theory fascinating not because I think it's plausible but because those who do are actually trying to account for the enormous amount of apparently intelligent engineering and design manifested by the fine-tuning of our universe without having to concede that theism is true. They are right, I think, to see an intelligence behind the universe, but wrong if they conclude that the intelligence is anything less than the Maximally Great Being posited by theism.

There's a good article by computer expert Peter Kassan at Skeptic.com in which he explains the simulation hypothesis and offers several criticisms of it.

Here's his summary of the argument for thinking we actually live in a computer simulation:

• The universe contains a vast number of stars.
• Some of these stars have planets.
• Some of these planets must be like Earth.
• Since intelligent life arose and eventually invented computers on Earth, intelligent life must have arisen and invented computers on some of these planets.
• It is (or inevitably will be) possible to simulate intelligent life inhabiting a simulated reality on a computer.
• Since it’s possible, it must have been done.
• There must be a vast number of such simulations on a vast number of computers on a vast number of planets.
• Since there’s only one real universe but there’s a vast number of simulations, the probability that you’re living in a simulation approaches one, while the probability that you’re living in the real universe approaches zero.

As Kassan observes there is no empirical evidence for, or testable implications of, this argument. It's therefore not a scientific hypothesis. It's more akin to science fiction or theology. Kassan calls it "cybernetic solipsism". There’s little reason, he says, to argue that anyone else in your simulated universe is conscious — to achieve verisimilitude, there’d be no need to actually program anyone else’s consciousness but yours.

More than that, though, even an immensely powerful computer would not be able to program human consciousness:

But even a superdupercomputer wouldn’t produce even a single conscious being. The crucial move in the argument is that the simulation of a human mind would actually be conscious in the same sense that you and I are.

Your computer simulation wouldn’t simply behave exactly like a real person, it would actually feel pain, pleasure, lust, fear, anger, love, nausea, angst, ennui, and everything else you can feel.

It would actually experience the same optical (and other sensory) illusions you do. It would feel what you feel when you get sick, or when you drink or take drugs. It would fall asleep and dream, and then wake up to realize that it was only dreaming. Presumably, it would even die.

In other words, the qualia or phenomena of sensory experience would have to somehow emerge from the whirrings of the computer's hard drive, but a physical computer can only produce physical outputs, and our sensations - pain, color, sound, etc. - are not physical or material.

They're produced by physical stimuli, they're generated by electrochemical reactions in our nervous system, but the sensation of blueness when we look at the sky, to take one example, is not itself physical.

In other words, our conscious experience is not simulatable and therefore we cannot be a simulation.

I'll have more on Kassan's argument tomorrow.