"I shall provide a physical foundation for eschatology—the study of the ultimate future—by making the physical assumption that the universe must be capable of sustaining life indefinitely... for infinite time... [W]e have to have some theory for the future of the physical universe—since it unquestionably exists— and this is the most beautiful postulate: that total death is not inevitable. All other theories of the future necessarily postulate the ultimate extinction of everything... there is nothing uglier than extermination. We physicists know that a beautiful postulate is more likely to be correct than an ugly one. Why not adopt the Postulate of Eternal Life, at least as a working hypothesis?"