David Chalmers

Virtual reality involves an immersive, interactive, computer-generated space.

At this point, we can ask, “How do you know you’re not in a computer simulation right now?”

How do you know anything at all about the reality outside you?

How do you know that your perception of the world is not an illusion?

Thinking about virtual reality gave me a new perspective.

The central thesis of this book is: Virtual reality is genuine reality. Or at least, virtual realities are genuine realities. Virtual worlds need not be second-class realities. They can be first-class realities.
We can break down this thesis into three parts:
Virtual worlds are not illusions or fictions, or at least they need not be. What happens in VR really happens. The objects we interact with in VR are real.
Life in virtual worlds can be as good, in principle, as life outside virtual worlds. You can lead a fully meaningful life in a virtual world.
The world we’re living in could be a virtual world. I’m not saying it is. But it’s a possibility we can’t rule out.

Each virtual world is a new reality: Reality+. Augmented reality involves additions to reality: Reality+. Some virtual worlds are as good as or better than ordinary reality: Reality+. If we’re in a simulation, there is more to reality than we thought: Reality+. There will be a smorgasbord of multiple realities: Reality+.

Technophilosophy is a combination of (1) asking philosophical questions about technology and (2) using technology to help answer traditional philosophical questions.

Thinking about the simulation hypothesis and the it-from-bit hypothesis—two ideas inspired by modern computers—yields the beginnings of a response to Descartes’s classic problem.