(Computer) Programs

I have settled on a simple test for judging claims, including Dennett’s, to have explained the nature of consciousness (or any other computational task): if you can’t program it, you haven’t understood it. Turing invented his test in the hope of bypassing all those philosophical problems. In other words, he hoped that the functionality could be achieved before it was explained. Unfortunately it is very rare for practical solutions to fundamental problems to be discovered without any explanation of why they work. — David Deutsch, The Beginning of Infinity: Explanations That Transform the World

If two programs respond in the same way to every possible action by the user, then they render the same environment; if they would respond perceptibly differently to even one possible action, they render different environments. — David Deutsch, The Fabric of Reality: The Science of Parallel Universes — and Its Implications

If it turns out that all this time we have merely been studying the programming of a cosmic planetarium, then that would merely mean that we have been studying a smaller portion of reality than we thought. So what? Such things have happened many times in the history of science, as our horizons have expanded beyond the Earth to include the solar system, our Galaxy, other galaxies, clusters of galaxies and so on, and, of course, parallel universes. — David Deutsch, The Fabric of Reality: The Science of Parallel Universes — and Its Implications

If you can’t program it, you haven’t understood it. — David Deutsch, The Beginning of Infinity: Explanations That Transform the World