One benefit future generations emphatically will have from us and past generation is the enormous body of knowledge, technology and infrastructure.

There's no guarantee that another dark age won't cause that knowledge to be lost to future generations. Hard to imagine in today's world, where the knowledge is spread around the globe, but not impossible. Just picture the ignorant masses running wild with the state's blessing as in China's Cultural Revolution in the '60s & '70s, or the Nazis book burning sessions in the '30s. I'm sure there are many of the religious right who would be happy to see a similar thing happen to science text books, particularly those that mention evolution.

I also think that those generations to come should not weigh on our obligations so heavily that we should seek to obviate all problems they might face; but we should also be aiming to give them a reasonable set of conditions to solve any problems we know about and others that arise. One benefit future generations emphatically will have from us and past generation is the enormous body of knowledge, technology and infrastructure. This is no small advantage to those who have it and we should strive to spread many of these benefits across the globe as well as down the timeline.

As I said, the moral interests of merely potential individuals can't be factored into a decision in universal utilitarianism. Logically it has to be this way, because the number of potential people is unlimited, and trying to take all their hypothetical interests into account would result in moral paralysis. (Would we all be morally obligated to have as many children as possible, to "fulfill" the "desires" of potential people to come into existence? Obviously this is absurd.)

Of course, any potential person who crosses the line into actuality does have real moral interests, which is why it would be wrong for, say, a pregnant mother to drink heavily or to smoke. An embryo doesn't have moral interests that can be harmed, but a child does, and if that embryo becomes a child then she is responsible for the harm it suffers from her actions.

However, there is one exception to this rule, and it's the one mcv mentioned. While it would be absurd to try to consider the moral interests of specific potential people, it's not at all absurd to consider the moral interests of the next generation as a whole. We can never know if any specific potential person may come into existence, but absent some exceptional circumstances, we can know that there will be a next generation of human beings, and we can assume that they'll have some general needs and desires (e.g., clean air and water) which we should provide. Just as the pregnant mother who smokes harms her child and therefore does wrong, even if the child doesn't yet exist at the time she commits her act, so too would ravaging the environment harm the next generation which we know will come into existence at some point.

This conclusion highlights what I see as an important point in the moral system of universal utilitarianism: merely potential people, people who do not yet exist, can exert no moral claim on us

In light of this statement how would you justify or explain why should we care for the enivironment. Let's suppose that we know for certain that some method we use to harvest the resourceses of the World would seriously damage the enivronment and the life of the people, but the damages would come in affect long after everyone who lived while this practise was going on are dead.

If potential people have no moral claim on us then we should not have a problem ruining the life of the people who will be living here 300 years from now, but for a lot of people (including me) this seems counter-intuitive.

If you read Stephen Pinker's "The Blank Slate" you will see that identical twins are more alike, even when raised separately. Siblings are less alike than twins, but more alike than adopted children raised in the same environment. We are not born blank slates. Nature has more to due with our personalities than nurture, and our peer groups as children have a larger impact on who we become than our parents do.

Uh, the fact that similarity in personality correlates with genetic similarity supports the idea that genetics contributes to personality development, which to my knowledge no one now contests. It does NOT follow that the contributions of environment and learning are negligible (for one thing, if that were true, cognitive therapy would never work).

Just a personal note to say it doesn't take cloning to produce an individual "who'd be subject to an impossible and autonomy-defying set of expectations." I was born nigh on to 70 years ago to replace a 13 year old sister who had died 3 years before. She happened to be buried a short walk from the back of our home, and for the first several years of my life I walked hand in hand with my Mother to her gravesite, was made to kiss her gravestone, heard stories of how good and beautiful she had been, and so on, even to being shown where she had been "laid out" in our home for burial, how many people had come to the funeral, and in countless other ways reminded I was, after all, only a boy. No matter what my accomplishments in life, I have never felt right or whole or satisfactory, and to this day i live in the shadow of a woman (girl) I never met.

I'm confident there are many others who can attest that impossible and autonomy-defying expectations occur independently of cloning.