Science

The Simulation Argument

If sufficiently advanced civilizations can run ancestor simulations, and if many do, then the number of simulated minds vastly outnumbers real ones. Given those odds, aren't we almost certainly simulated?

Philosopher Nick Bostrom formalized this argument in 2003. It doesn't claim we're definitely in a simulation. It claims that one of three propositions must be true, and two of them are uncomfortable. The third, that we're probably simulated, is the most disquieting option.

Bostrom, N. (2003). Are You Living in a Computer Simulation? Philosophical Quarterly, 53(211), 243–255.

The trilemma

Bostrom argues that at least one of these must be true:

  1. Nearly all civilizations go extinct before reaching the capability to run realistic simulations.
  2. Nearly all civilizations that could run simulations choose not to.
  3. We are almost certainly living in a computer simulation.

If (1) and (2) are both false, if civilizations survive and choose to simulate, then simulated minds vastly outnumber "real" ones. A random mind would be far more likely to be simulated.

What would change if we knew

If we're in a simulation:

  • The "base reality" might have different physical laws than ours
  • Our universe could be paused, rerun, or edited
  • The simulators might be able to intervene, and might have

If we're not:

  • We're likely an early civilization (before the great filter, if there is one), or
  • Something about consciousness or computation makes large-scale ancestor simulations impossible or undesirable

The objections

  • We can't test it: any evidence of simulation could also be a coincidence. A non-falsifiable hypothesis.
  • It doesn't matter: if the simulation is indistinguishable from base reality, nothing about your life changes.
  • Infinite regress: if we're simulated, the simulators might be too, and so on. The argument doesn't privilege any level.

The question it leaves

If you found out you were simulated, would anything feel different? And if nothing would feel different, does the distinction between "real" and "simulated" mean anything?

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