Despite the unrivaled empirical success of quantum theory, the very suggestion that it may be literally true as a description of nature is still greeted with cynicism, incomprehension, and even anger.
David DeutschIf 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.
David DeutschHumans 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 DeutschTime 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 DeutschLike 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