Nick Bostrom's Rigorous Trilemma
The Simulation Argument
At least one of these is almost certainly true: (1) civilizations always die before making simulations, (2) civilizations never want to run ancestor simulations, (3) you are in a simulation right now.
Common Misconception
“The simulation hypothesis is unfalsifiable philosophical speculation - just stoner talk dressed up in academic language.”
This is wrong. The Simulation Argument, published by philosopher Nick Bostrom in 2003, is not a claim that we ARE in a simulation. It is a rigorous logical argument that establishes a trilemma: a set of three mutually exhaustive options where at least one MUST be true.
The argument does not tell you which horn to accept. But it proves you cannot escape all three. You must pick your poison.
“At least one of the following propositions is true: (1) the human species is very likely to go extinct before reaching a 'posthuman' stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history; (3) we are almost certainly living in a computer simulation.”- Nick Bostrom, 2003
The Three Horns of the Trilemma
Click each option to explore its implications. Remember: you can reject any two, but you must accept at least one.
The key insight: These three options are mutually exhaustive. At least one MUST be true. The argument does not tell you WHICH one - only that you must pick your poison.
The Math That Forces the Conclusion
The power of the argument comes from a simple mathematical observation: if even ONE civilization survives and runs ancestor simulations, the number of simulated beings becomes astronomical compared to real beings.
Adjust the parameters below. Notice how even very conservative estimates lead to overwhelming odds of being simulated - IF civilizations survive AND simulate.
Simulated beings per base reality being
100.0B : 1
P(Base Reality)
< 0.01%
P(Simulated)
100.0000%
Observer Distribution
// The core equation
f_sim = (f_p * f_i * N * H) / (1 + f_p * f_i * N * H)
Where: f_p = survival fraction, f_i = simulation fraction, N = sims per civ, H = beings per sim
With these parameters, if civilizations survive and simulate, you are almost certainly in a simulation. The math is simply overwhelming.
The math is simple but devastating. If posthuman civilizations run N simulations with M conscious beings each, then for every “real” observer, there are N*M simulated observers. Even modest values make the ratio astronomical.
Visualizing the Branching Civilizations
Watch civilizations branch and simulate. Some go extinct, some survive, some create simulations that contain civilizations that might simulate further.
Real Beings
1B
Simulated Beings
0B
P(You Are Simulated)
0.0%
Pick Your Poison
The argument does not force you to believe we ARE in a simulation. It forces you to accept at least one of three uncomfortable conclusions. Which do you reject?
The argument does not tell you which horn is true. But it forces you to accept at least one. Which do you reject?
Notice: You cannot escape the trilemma by simply rejecting it. The argument is not a claim about what IS true, but a logical constraint on what CAN be true.
Why You Should Bet You Are Simulated
The argument relies on a key philosophical principle: if you cannot distinguish between being a “real” observer and a simulated one from the inside, you should assign probabilities based on observer counts.
If you cannot tell from inside which type of observer you are, rationality demands you assign probabilities based on the relative frequencies of observer types.
Thought Experiment: The Two Urns
You are a ball drawn from one of these urns. You cannot see your own color. Which urn were you more likely drawn from?
The Self-Sampling Assumption: One should reason as if one is a random sample from the set of all observers in one's reference class. If simulated observers exist and vastly outnumber real ones, you should bet you are simulated.
Responding to Objections
The Simulation Argument has survived two decades of scrutiny. Here are the most common objections and why they do not escape the trilemma.
The Takeaway
The Simulation Argument is not a claim about what IS true. It is a logical constraint on what CAN be true. You must accept at least one:
Civilizations die
They choose not to simulate
You are simulated
Pick your poison. There is no fourth option.
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Reference: Bostrom (2003)