David Deutsch quotes

David Deutsch is a British physicist and pioneer in the field of quantum computation. His groundbreaking work laid the foundation for quantum computers and expanded our understanding of quantum mechanics. He is also recognized for his contributions to the philosophy of science, particularly through the multiverse interpretation of quantum theory. Here are 32 of his quotes:

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

David Deutsch

Our best theories are not only truer than common sense, they make more sense than common sense...

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

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

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.

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

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

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

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

David Deutsch

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

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

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

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.

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

The most important application of quantum computing in the future is likely to be a computer simulation of quantum systems, because that's an application where we know for sure that quantum systems in general cannot be efficiently simulated on a classical computer.

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

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.

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 brain is the only kind of object capable of understanding that the cosmos is even there, or why there are infinitely many prime numbers, or that apples fall because of the curvature of space-time, or that obeying its own inborn instincts can be morally wrong, or that it itself exists.

David Deutsch

Is the human race a universal constructor?

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