Wolfgang Schwarz

Are we living in a computer simulation?

I'm moderately confident that I don't live in a computer simulation. My reasoning goes like this.

1. A priori, simulation scenarios are less probable than non-simulation scenarios.

2. My evidence is more likely in non-simulation scenarios than in simulation scenarios.

3. So: It is highly improbable, given my evidence, that I'm in a simulation scenario.

By a "simulation scenario", I mean a scenario in which a subject's experiences of themselves and their environment are generated by a computer program that simulates an ordinary (non-simulated) subject and their environment.

I assume that it is a priori possible for a computer program to generate experiences (and a "subject") by simulating an ordinary subject with experiences. I'm not 100% sure this is true. (If not, premise 1 can be strengthened: simulation scenarios have probability 0.) But it seems plausible, especially if we're liberal about what qualifies as a computer program and as a simulation.

Integrating centred information

Sensory information is centred. Right now, for example, my visual system conveys to me that there's a red wall about 1 metre ahead (among much else); it does not convey that Wolfgang Schwarz is about 1 metre away from a red wall on 22 January 2026 at 12:04 UTC.

We can quibble over what exactly is part of the sensory information. We can also quibble over what "sensory information" is even meant to be. But it should be uncontroversial that we gain information from our senses. My point is that, on any plausible way of spelling this out, the information we receive is centred: it doesn't have parameters that fix a unique location in space and time. If I were unsure about what time it is or who I am, looking at the wall in front of me wouldn't help. The underlying reason, of course, is that photoreceptors are insensitive to differences in spatiotemporal location: they don't produce different outputs depending on where or when they are activated by photons.