Many things have been posited as the ideal toward which all humans should strive, but in the end, when there is no longer any humanity existing, when there are no humans to value these strivings, then our ethics and values become utterly meaningless—at least to us humans. To maximize humanity then becomes the goal toward which all humans should strive. This is a natural striving, and the foundation upon which all life, not just human life, has evolved.
However, at some time in the future the species we call human will cease to exist. Hopefully this will be a very long time into the future, but a billion more years of human existence is too much to even fantasize, being double the time span of multicellular life, and perhaps a million years is beyond any reasonable hope, being the outside limit of human-like species, but perhaps a thousand years might be reasonably expected if we can control ourselves. However, with super weapons such as 30,000 H-bombs currently available to humanity it seems questionable that we can survive even for one hundred years and our half life expectancy is probably more like ten years at present. It is that rather pessimistic time horizon upon which the very grim Lifehaven Project is founded, and the not quite so grim, but much broader Earth Ark is planned.
Once we admit to ourselves that we personally are mortal, and that we will at some time no longer exist, it becomes only a small step to realize that at some point in time even our species will cease to exist. When we do that, and project our viewpoint far into the future, we can then view humanity from outside of itself, and discuss objectively how well it performed as a species, and what it might have done differently to have done better or worse.
The world presented itself to our ancestors as a vast place where they were, but a few people, and they were only very small players in the wonder of it all. But now we humans are very numerous, and are dominating the natural environment to the point of destruction. The environmental impact of any individual would be easily accommodated by the Earth but not 6.8 billion of us. And then with our currently existing science, and growing knowledge of the elemental forces available in the world, it has now become possible in a day to destroy us all. With the human problems that arise even in our time of abundance there are some people who will risk it all, and everything humanity has, to gain a political advantage. There are always claimed to be good reasons for a particular war, but in a world with H-bombs the claimed good reasons may well end up destroying all humanity, and then there will be no one left to appreciate those reasons or any other good reasons. All will be lost.
Thus, the maximizing of humanity’s life becomes my prime ethical directive, and defining just what that is, and how it might be achieved becomes the practical goal. Many definitions might be offered but what seems most fundamental is the total quantity of time that the humans lived as measured from some distant time in the future. (The total number of minutes of human happiness might be wonderful, but it’s a too rarefied definition and harder to discuss than just living.)
By this approach the present human population of 6.8 billion people living for one year would be 6.8 billion people years. Alternatively, 6.8 million people living for one thousand years would be 6.8 billion people years. That is, people lived the same number of years, the difference is that the Earth can probably support 6.8 million people for a thousand years, perhaps a thousand times as long, and even so much as a million years. But probably the Earth can not support 6.8 billion people for a hundred years and possibly not even ten years. From the perspective of a distant viewer maximizing the years of human life it is better to have a smaller number for a much longer period of time.
If the the totality of human existence is defined as the prime virtue then the problem that needs to be solved is how to limit human population to a number that can be easily sustained permanently. That virtue is in direct contradiction to evolutionary imperatives to maximize short term population. The way we are currently functioning is as a species of wild animals, which at present is the top predator taking advantage of all that we are capable of subduing. There is nothing to contain us other than ultimate limitations of resources, and when those limits are approached there will be massive conflict, which includes H-bombs and biological warfare. If somehow humans could be converted into a domesticated species, and respond to our environment in a moderated way, in balance with it, then there would be hope for a long future, which would maximize the human values of happy, healthy, wise and wealthy.
Clearly this type of condition can not exist between contending nation states, and there must be some sort of overriding humanity wide law. Within nation states there are laws which control their members, and if this obedience to laws could be established worldwide for all people then it would be only a small step from where we are to where we need to go. But it would require giving up national sovereignty over H-bombs and an invasion of their property to assure that some individual groups were not creating these monstrous weapons. On a daily basis the average person would have an idyllic life because all of the reasons for conflict could be cared for by already existing laws. In a stable world everyone could have a two child family which most people seem to desire.