According to David Deutsch, the fundamental theories that explain the reality boil down to: (a) many-world interpretation of quantum physics; (b) Turing’s theory of computation; (c) neo-Darwinian theory of evolution; (d) Popperian epistemology. His first book, The Fabric of Reality, explains how each theory is dependent on others, and his second book, The Beginning of Infinity, explores the implication of the worldview that consists of all four theories. The interdependencies between the four theories are summarized below. It is my view that the argument in The Beginning of Infinity can be derived by taking the four strands seriously. It is also my view that other theories—whether scientific, philosophical, or cultural (e.g., Constructor Theory, Peircean semiotics, Austrian Economics)—can be superimposed on the four strands to the extent that they are compatible with, derivable from , or instantiations of the four.
Interdependencies
1. The multiverse and explanation
Knowledge consists of explanation—and to the extent that the best explanation evokes the multiverse, it must be real.
2. The multiverse and evolution
The theory of evolution relies on causal explanation—and causal explanation makes sense because the variants really exist somewhere in the multiverse.
3. The Turing principle and knowledge creation
Knowledge creation is possible because it is allowed in the laws of physics. Knowledge can be improved indefinitely. Mathematics is not about discovering absolute truths—it is as creative, fallible, and physical, as other knowledge creating processes.
4. Knowledge creation and evolution
Simply put, knowledge creation is evolution—the difference is whether it is mediated via memes or genes.
5. The Turing principle and evolution
Evolution—a special type of knowledge creation—is possible because it is allowed in the laws of physics.
6. The multiverse and computation
Computation—information processing—is possible because it is allowed in the laws of physics. Put differently, there will be no information without the multiverse, because the characteristic feature of the former is how it could’ve been otherwise—incomprehensible conception without the multiverse. And quantum computers can be explained only by evoking the multiverse—computation reveals the multiverse, as it were. Another way to put it: computation is a physical process.