A proper calculation using Bayes' theorem is missing in the article. The
conclusion is false.
E.g. let's assume that (2) and (3) are false. So, we know with almost 100%
certainty that we are not living in a simulation, and we know with almost
100% certainty that a posthuman civilization is going to run significant
number of simulations of their evolutionary history.
Concluding that (1) must be true is thus precisely the Doomsday argument
which is false because of improper Bayesian reasoning:
The principle of indifference is used while the self indicating assumption
This is a logical inconsistency which leads to erroneous conclusions.
Nick Bostrom wrote:
``I have just finished a paper (which had been existing in a half-baked form
for much too long) that might be of interest to the list members. It has its
own website at http://www.simulation-argument.com (which also contains a few
Are You Living In a Computer Simulation? Nick Bostrom (2001)
ABSTRACT. This paper argues that 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 (or
variations thereof); (3) we are almost certainly living in a computer
simulation. It follows that the transhumanist dogma that there is a
significant chance that we will one day become posthumans who run
ancestor-simulations is false, unless we are currently living in a
simulation. A number of other consequences of this result are also