People

Like every other destruction of optimism, whether in a whole civilisation or in a single individual, these must have been unspeakable catastrophes for those who had dared to expect progress. But we should feel more than sympathy for those people. We should take it personally. For if any of those earlier experiments in optimism had succeeded, our species would be exploring the stars by now, and you and I would be immortal. — David Deutsch, The Beginning of Infinity: Explanations That Transform the World

The only uniquely significant thing about humans (whether in the cosmic scheme of things or according to any rational human criterion) is our ability to create new explanations, and we have that in common with all people. You do not become less of a person if you lose a limb in an accident; it is only if you lose your brain that you do. Changing our genes in order to improve our lives and to facilitate further improvements is no different in this regard from augmenting our skin with clothes or our eyes with telescopes. — David Deutsch, The Beginning of Infinity: Explanations That Transform the World

Very little in nature is detectable by unaided human senses. — David Deutsch, The Beginning of Infinity: Explanations That Transform the World

There can be only one type of person: universal explainers and constructors. — David Deutsch, The Beginning of Infinity: Explanations that Transform The World

People are significant in the cosmic scheme of things; and The Earth’s biosphere is incapable of supporting human life. — David Deutsch, The Beginning of Infinity: Explanations that Transform The World

Thus the issue of whether it is becoming harder or easier to understand everything that is understood depends on the overall balance between these two opposing effects of the growth of knowledge: the increasing breadth of our theories, and their increasing depth. Breadth makes it harder; depth makes it easier. One thesis of this book is that, slowly but surely, depth is winning. In other words, the proposition that I refused to believe as a child is indeed false, and practically the opposite is true. We are not heading away from a state in which one person could understand everything that is understood, but towards it. — David Deutsch, The Fabric of Reality: Towards a Theory of Everything

Person: An entity that can create explanatory knowledge. — David Deutsch, The Beginning of Infinity: Explanations That Transform the World

The first person to measure the circumference of the Earth was the astronomer Eratosthenes of Cyrene, in the third century BCE. His result was fairly close to the actual value, which is about 40,000 kilometres. For most of history this was considered an enormous distance, but with the Enlightenment that conception gradually changed, and nowadays we think of the Earth as small. — David Deutsch, The Beginning of Infinity: Explanations That Transform the World

To the extent that we are on a ‘spaceship’ [i.e. planet earth], we have never been merely its passengers, nor (as is often said) its stewards, nor even its maintenance crew: we are its designers and builders. Before the designs created by humans, it was not a vehicle, but only a heap of dangerous raw materials. — David Deutsch, The Beginning of Infinity: Explanations That Transform the World

But, while a society lasted, all important areas of life seemed changeless to the participants: they could expect to die under much the same moral values, personal lifestyles, conceptual framework, technology and pattern of economic production as they were born under. And, of the changes that did occur, few were for the better. I shall call such societies ‘static societies’: societies changing on a timescale unnoticed by the inhabitants. — David Deutsch, The Beginning of Infinity: Explanations That Transform the World

The moral component of the Spaceship Earth metaphor is therefore somewhat paradoxical. It casts humans as ungrateful for gifts which, in reality, they never received. And it casts all other species in morally positive roles in the spaceship’s life-support system, with humans as the only negative actors. But humans are part of the biosphere, and the supposedly immoral behaviour is identical to what all other species do when times are good – except that humans alone try to mitigate the effect of that response on their descendants and on other species. — David Deutsch, The Beginning of Infinity: Explanations That Transform the World

Would we seem like insects to it? This can seem plausible only if one forgets that there can be only one type of person: universal explainers and constructors. The idea that there could be beings that are to us as we are to animals is a belief in the supernatural. — David Deutsch, The Beginning of Infinity: Explanations That Transform the World

Changing our genes in order to improve our lives and to facilitate further improvements is no different in this regard from augmenting our skin with clothes or our eyes with telescopes. — David Deutsch, The Beginning of Infinity: Explanations That Transform the World

In early prehistory, populations were tiny, knowledge was parochial, and history-making ideas were millennia apart. In those days, a meme spread only when one person observed another enacting it nearby, and (because of the staticity of cultures) rarely even then. So at that time human behaviour resembled that of other animals, and much of what happened was indeed explained by biogeography. — David Deutsch, The Beginning of Infinity: Explanations That Transform the World