David Deutsch Quotes

The rational thing for a layperson to do is to take seriously the prevailing scientific theory.

Think of all our knowledge-generating processes, our whole culture and civilization, and all the thought processes in the minds of every individual, and indeed the entire evolving biosphere as well, as being a gigantic computation. The whole thing is executing a self-motivated, self-generating computer program. More specifically it is, as I have mentioned, a virtual-reality program in the process of rendering, with ever-increasing accuracy, the whole of existence.

If something is permitted by the laws of physics, then the only thing that can prevent it from being technologically possible is not knowing how.

Surely it is more interesting to argue about what the truth is, than about what some particular thinker, however great, did or did not think.

Any theory about improvement raises the question: how is the knowledge of how to make that improvement created? Was it already present at the outset? The theory that it was is creationism. Did it ‘just happen’? The theory that it did is spontaneous generation.

That progress is both possible and desirable is perhaps the quintessential idea of the Enlightenment. It motivates all traditions of criticism, as well as the principle of seeking good explanations. But it can be interpreted in two almost opposite ways, both of which, confusingly, are known as ‘perfectibility’. One is that humans, or human societies, are capable of attaining a state of supposed perfection – such as the Buddhist or Hindu ‘nirvana’, or various political utopias. The other is that every attainable state can be indefinitely improved. Fallibilism rules out that first position in favour of the second.

A prediction, or any assertion, that cannot be defended might still be true, but an explanation that cannot be defended is not an explanation.

As I understand it, the claim is that the less you use Homeopathy, the better it works. Sounds plausible to me.

Quantum computation is … nothing less than a distinctly new way of harnessing nature … It will be the first technology that allows useful tasks to be performed in collaboration between parallel universes, and then sharing the results.

Since building a universal virtual-reality generator is physically possible, it must actually be built in some universes.

To say that prediction is the purpose of a scientific theory is to confuse means with ends. It is like saying that the purpose of a spaceship is to burn fuel. … Passing experimental tests is only one of many things a theory has to do to achieve the real purpose of science, which is to explain the world.

It is possible to build a virtual-reality generator whose repertoire includes every possible environment.

Kuhn's theory suffers from a fatal flaw. It explains the succession from one paradigm to another in sociological or psychological terms, rather than as having primarily to do with the objective merit of the rival explanations. Yet unless one understands science as a quest for explanations, the fact that it does find successive explanations, each objectively better than the last, is inexplicable.

Let me define that [wealth] in a non-parochial way as the repertoire of physical transformations that they would be capable of causing.

Reality contains not only evidence, but also the means (such as our minds, and our artefacts) of understanding it. There are mathematical symbols in physical reality. The fact that it is we who put them there does not make them any less physical.