132 Will Robots Inherit the Earth? THE FAILURES OF ETHICS This article bears on our rights to have children, to change our genes, and to die if we so wish. No popular ethical system yet, be it humanist or religion-based, has shown itself able to face the challenges that already confront us. How many people  should  occupy  Earth?  What  sorts  of  people  should they be? How should we share the available space? Clearly, we must change our ideas about making additional children. Individuals now are conceived by chance. Someday, though, they could be ‘composed’ in accord with considered desires and designs. Furthermore, when we build new brains, these need not start out the way ours do, with so little knowledge about the world. What sorts of things should our new chil- dren know? How many of them should we produce and who should decide their attributes? Whatever the unknown future may bring, already we are changing the rules that made us. Although most of us will be fearful of change, others will surely want to escape from our present limitations. When I decided to write this article, I tried these ideas out on several groups and had them respond to informal polls. I was amazed to find that at least three quar- ters of the audience seemed to feel that our life spans were already too long. “Why would anyone want to live for five hundred years? Wouldn’t it be boring? What if you outlived all your friends? What would you do with all that time?” they asked. It seemed as though they secretly feared that they did not deserve to live so long. I find it rather worrisome that so many people are resigned to die. My scientist friends showed few such concerns. “There are countless things that I want to find out, and so many problems I want to solve, that I could use many centuries,” they said. Certainly, immortality would seem unattractive if it meant endless infirmity, debility, and dependency upon others – but