249 Essays on Infinite Lifespans   Marc Geddes extropian transhumanist Max More would disagree, regarding the concept of ‘self’ as perfectly meaningful. [5] The philoso- phy and science of the mind is currently not advanced enough to provide an answer to the question of the self. So long as a living being retains memories of his past, there is a connection between its past and present selves which may be sufficient for it to retain the same sense of ‘self’. In order to remember our past, our current self has to be ‘backwards compatible’ with all our past selves. A related worry is that an extremely long-lived person would somehow cease to be human. Yet human nature itself is not fixed.  Human  beings  have  constantly  re-invented  them- selves  through  cultural  change  and  new  technology  argues Transhumanist  philosopher  Nick  Bostrom.  [6]  Even  if  it would  be  true  that  someone  who  lived  hundreds  of  years started to change into a different entity, why should this be feared? After all, a man at 20 years is rather different to a man at 5 years, just as the man at 60 years is rather different to the man at 20. But the potential for change is precisely what makes life exciting and creates the opportunity for something better  to  come  along.  And  consider  the  alternative:  death. Did we not agree that life is generally better than death? Better to evolve than die! RELIGION Some people may object to the quest for immortality on religious grounds. It is argued that extremely long life is some- how un- natural, that it is ‘against God’s plan’. Yet some of the strongest allies of the quest for immortality may come from those of Jewish faith. In Judaism the primary metaphor for God is that “God is Life”. Judaism may be the religion most