I dislike intro-level philosophy classes. Invariably, a student asks whether this world is merely a ‘matrix’. The question usually elicits an eye-roll from me—not because it’s a bad one, but because it’s so tired and clichéd. (And the question is made all the more obnoxious by the fact that the student thinks he or she is volunteering something novel.) So I’ve kind of dismissed the thought about living in a matrix as an amateurish musing popularized by a silly movie. But recently, I’ve encountered a more sophisticated articulation of this issue.
In a debate last month, atheist author Sam Harris made an interesting secular argument for the afterlife. It’s known as the simulation argument, and it was first formulated by Swedish philosopher Nick Bostrom. Bostrom contends that it’s likely we live in a simulated world, and this conclusion rests on pretty sound assumptions. I’ll let him explain the logic in his own words:
The formal version of the argument requires some probability theory, but the underlying idea can be grasped without mathematics. It starts with the assumption that future civilizations will have enough computing power and programming skills to be able to create what I call “ancestor simulations”. These would be detailed simulations of the simulators’ predecessors—detailed enough for the simulated minds to be conscious and have the same kinds of experiences we have. Think of an ancestor simulation as a very realistic virtual reality environment, but one where the brains inhabiting the world are themselves part of the simulation.
The simulation argument makes no assumption about how long it will take to develop this capacity. Some futurologists think it will happen within the next 50 years. But even if it takes 10 million years, it makes no difference to the argument.
Let me state what the conclusion of the argument is. The conclusion is that at least one of the following three propositions must be true:
1. Almost all civilizations at our level of development become extinct before becoming technologically mature.
2. The fraction of technologically mature civilizations that are interested in creating ancestor simulations is almost zero.
3. You are almost certainly living in a computer simulation.
How do we reach this conclusion? Suppose first that the first proposition is false. Then a significant fraction of civilizations at our level of development eventually become technologically mature. Suppose, too, that the second proposition is false. Then a significant fraction of these civilizations run ancestor simulations. Therefore, if both one and two are false, there will be simulated minds like ours.
If we work out the numbers, we find that there would be vastly many more simulated minds than nonsimulated minds. We assume that technologically mature civilizations would have access to enormous amounts of computing power.
So enormous, in fact, that by devoting even a tiny fraction to ancestor simulations, they would be able to implement billions of simulations, each containing as many people as have ever existed. In other words, almost all minds like yours would be simulated. Therefore, by a very weak principle of indifference, you would have to assume that you are probably one of these simulated minds rather than one of the ones that are not simulated. (New Scientist, 2006)
It’s important to note that Bostrom’s trilemma does not necessarily show that we are living in a simulated reality, only that it’s one of three possibilities. “In reality,” he writes, “we don’t have much specific information to tell us which of the three propositions might be true. In this situation, it might be reasonable to distribute our credence roughly evenly between them.”
Still, I get the impression that he leans toward the third proposition, that of simulated reality, given his discussion of the other options.
Proposition one is straightforward. For example, maybe there is some technology that every advanced civilization eventually develops and which then destroys them. Let us hope this is not the case.
Proposition two requires that there is a strong convergence among all advanced civilizations, such that almost none of them are interested in running ancestor simulations. One can imagine various reasons that may lead civilizations to make this choice. Yet for proposition two to be true, virtually all civilizations would have to refrain. If this were true, it would be an interesting constraint on the future evolution of intelligent life.
Building on Bostrom’s argument, Sam Harris suggests that some of these simulated worlds will include an afterlife, because these simulations would likely reflect the religious beliefs of their creators. A Mormon would then simulate a reality in which Mormonism is true, a Hindu would simulate a reality in which Hinduism is true, and so on.
What do you think of these arguments, and, if correct, what would their implications for our everyday lives be?