David Deutsch Quotes

“Every problem that is interesting is also soluble.”

“I chop and change between what is called 'work' and what is called 'recreation.' There are no discontinuities in my day. I only play tennis with people I find interesting.”

“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.”

“If you reject the infinite, you are stuck with the finite, and the finite is parochial... the best explanation of anything eventually involves universality, and therefore infinity. The reach of explanations cannot be limited by fiat.”

“No precautions, and no precautionary principle, can avoid problems that we do not yet foresee. We need a stance of problem-fixing, not just problem-avoidance.”

“All fiction that does not violate the laws of physics is fact.”

“An optimistic civilization is open and not afraid to innovate, and is based on traditions of criticism.”

“An unproblematic state is a state without creative thought. Its other name is death.”

“As the physicist Stephen Hawking put it, humans are ‘just a chemical scum on the surface of a typical planet that’s in orbit round a typical star on the outskirts of a typical galaxy’. The proviso ‘in the cosmic scheme of things’ is necessary because the chemical scum evidently does have a special significance according to values that it applies to itself, such as moral values. But the Principle says that all such values are themselves anthropocentric: they explain only the behaviour of the scum, which is itself insignificant.”

“Base metals can be transmuted into gold by stars, and by intelligent beings who understand the processes that power stars, but by nothing else in the universe.”

“Because we are universal explainers, we are not simply obeying our genes.”

“Consider the revolutionary utopians, who typically achieve only destruction and stagnation. Though they are blind optimists, what defines them as utopians is their pessimism that their supposed utopia, or their violent proposals for achieving and entrenching it, could ever be improved upon.”

“Good political institutions are those that make it as easy as possible to detect whether a ruler or policy is a mistake, and to remove rulers or policies without violence when they are.”

“If you can’t program it, you haven’t understood it.”

“Like an explosive awaiting a spark, unimaginably numerous environments in the universe are waiting out there, for aeons on end, doing nothing at all or blindly generating evidence and storing it up or pouring it out into space. Almost any of them would, if the right knowledge ever reached it, instantly and irrevocably burst into a radically different type of physical activity: intense knowledge-creation, displaying all the various kinds of complexity, universality and reach that are inherent in the laws of nature, and transforming that environment from what is typical today into what could become typical in the future. If we want to, we could be that spark.”

“Optimism is, in the first instance, a way of explaining failure, not prophesying success. It says that there is no fundamental barrier, no law of nature or supernatural decree, preventing progress.”

“Perhaps a more practical way of stressing the same truth would be to frame the growth of knowledge as a continual transition from problems to better problems, rather than from problems to solutions or from theories to better theories.”

“Some people become depressed at the scale of the universe, because it makes them feel insignificant. Other people are relieved to feel insignificant, which is even worse. But, in any case, those are mistakes. Feeling insignificant because the universe is large has exactly the same logic as feeling inadequate for not being a cow. Or a herd of cows. The universe is not there to overwhelm us; it is our home, and our resource. The bigger the better.”

“Sparta has no philosophers. That’s because the job of a philosopher is to understand things better, which is a form of change, so they don’t want it. Another difference: they don’t honour living poets, only dead ones. Why? Because dead poets don’t write anything new, but live ones do. A third difference: their education system is insanely harsh; ours is famously lax. Why? Because they don’t want their kids to dare to question anything, so that they won’t ever think of changing anything.”

“The Enlightenment was a way of pursuing knowledge with a tradition of criticism and seeking good explanations instead of reliance on authority.”

“There is only one way of thinking that is capable of making progress, or of surviving in the long run, and that is the way of seeking good explanations through creativity and criticism.”

“Those two overarching concerns are these: we Athenians are concerned above all with improvement; the Spartans seek only – stasis. Two opposite objectives.”

“To choose an option, rationally, is to choose the associated explanation. Therefore, rational decision-making consists not of weighing evidence but of explaining it, in the course of explaining the world. One judges arguments as explanations, not justifications, and one does this creatively, using conjecture, tempered by every kind of criticism. It is in the nature of good explanations – being hard to vary – that there is only one of them. Having created it, one is no longer tempted by the alternatives. They have been not outweighed, but out-argued, refuted and abandoned. During the course of a creative process, one is not struggling to distinguish between countless different explanations of nearly equal merit; typically, one is struggling to create even one good explanation, and, having succeeded, one is glad to be rid of the rest.”

“Very little in nature is detectable by unaided human senses.”

“Without error-correction all information processing, and hence all knowledge-creation, is necessarily bounded. Error-correction is the beginning of infinity.”

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

“The overwhelming majority of theories are rejected because they contain bad explanations, not because they fail experimental tests.”

“The whole scientific process resembles biological evolution. A problem is like an ecological niche, and a theory is like a gene or a species which is being tested for viability in that niche.”

“We do not experience time flowing, or passing. What we experience are differences between our present perceptions and our present memories of past perceptions. We interpret those differences, correctly, as evidence that the universe changes with time. We also interpret them, incorrectly, as evidence that our consciousness, or the present, or something, moves through time.”