Quotes by David Deutsch

As I understand it, the claim is that the less you use Homeopathy, the better it works. Sounds plausible to me.
– David Deutsch
Every problem that is interesting is also soluble.
– David Deutsch
I myself believe that there will one day be time travel because when we find that something isn't forbidden by the over-arching laws of physics we usually eventually find a technological way of doing it.
– David Deutsch
Is the human race a universal constructor?
– David Deutsch
It is possible to build a virtual-reality generator whose repertoire includes every possible environment.
– David Deutsch
Mathematical knowledge may, just like our scientific knowledge, be deep and broad, it may be subtle and wonderfully explanatory, it may be uncontroversially accepted; but it cannot be certain.
– David Deutsch
Necessary truth is merely the subject-matter of mathematics, not the reward we get for doing mathematics. The object of mathematics is not, and cannot be, mathematical certainty. It is not even mathematical truth, certain or otherwise. It is, and must be, mathematical explanation.
– David Deutsch
Our best theories are not only truer than common sense, they make more sense than common sense.
– David Deutsch
Quantum computation is... a distinctively new way of harnessing nature... It will be the first technology that allows useful tasks to be performed in collaboration between parallel universes.
– David Deutsch
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.
– David Deutsch
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.
– David Deutsch
The next chapter is likely to provoke many mathematicians. This can't be helped. Mathematics is not what they think it is.
– David Deutsch
The overwhelming majority of theories are rejected because they contain bad explanations, not because they fail experimental tests.
– David Deutsch
The quantum theory of parallel universes is not the problem, it is the solution. It is not some troublesome, optional interpretation emerging from arcane theoretical considerations. It is the explanation, the only one that is tenable, of a remarkable and counter-intuitive reality.
– David Deutsch
The theory of computation has traditionally been studied almost entirely in the abstract, as a topic in pure mathematics. This is to miss the point of it. Computers are physical objects, and computations are physical processes. What computers can or cannot compute is determined by the laws of physics alone, and not by pure mathematics.
– David Deutsch
The truly privileged theories are not the ones referring to any particular scale of size or complexity, nor the ones situated at any particular level of the predictive hierarchy, but the ones that contain the deepest explanations.
– David Deutsch
Time travel may be achieved one day, or it may not. But if it is, it should not require any fundamental change in world-view, at least for those who broadly share the world view I am presenting in this book.
– David Deutsch
Humans may or may not have cosmic significance, and if they do, it will be by hitching a ride on the objective centrality of knowledge in the cosmic scheme of things.
– David Deutsch