People do not sufficiently appreciate it, but individual choice totally changes what it means to be human. Throughout history, the character of human lives has been determined almost entirely by one of two things: nature and custom. Without doubt, custom has undergone a major assault in the modern era. Traditional authorities no longer have the power they once had, as more individuals are allowed to do what Kant saw as the necessary condition for enlightenment: thinking for oneself.
Modernity also saw instantiated the ages-old idea that human beings should be the masters of nature. Thanks to thinkers like Spinoza, Hume, and Darwin, intelligent people now realize that nature is indifferent to us, that life is the product of unintelligent natural forces and historical accidents. This is not an occasion for despair, but rather for maturity. There is no God to protect us. Even if there are powerful beings that exist outside the universe, there is no evidence to believe that they intervene in human affairs. As Hume persuasively argued in the Dialogues Concerning Natural Religion, the quality of the world suggests, at best, divine indifference.
Without some kind of theological argument, some assurance that nature tends toward human good, there is no reason to believe that the natural world is as it should be. If we understand evolution, we realize that forces like natural and sexual selection at best tend to the survival and reproduction of organisms, but not to their well-being. Human well being is an accident of nature. What that means, is that if we leave it up to nature, there's no reason to suppose it will happen.
The time has come to wage an assault on the natural world, much like the assault on tradition and custom that modernity has spawned. What is natural is not what is good. Human beings are the sole creators of value in this world, and we must not shy away from that responsibility. This is why everything that can be made into a matter of individual choice ought to be. This would be what it means to grow up as a species. Individual choice, if taken to its logical conclusions, is actually an extremely robust conception of freedom, and I will convince as many people as I can of this.
We are not sufficiently thinking about the long term. Global warming is one consequence of this, as are the various problems we face with energy supplies. However, the universe is teeming with energy, and we just have to figure out how to get at it to accomplish our ends. We must think beyond the challenges that we face today with the economy and the environment, and consider the future that awaits us and our offspring.
What kind of world do we want to live in? Science and technology will, within centuries if not sooner, give us the power to answer this question. We must not back down from it. But each individual must answer for themselves. If a person does not want to embrace maturity, if they want to stick to the old customary ideas, or to what nature has forced upon us, they should have that right. We should not force people to be free.
However, we should force them to reflect on their lives, and to set their own values and priorities. When more aspects of human identity come under our control, individuals will be forced to face this question: when is it worthwhile to expend time and effort in making a choice, and when is it okay to delegate those choices to others? It's a question of setting priorities. In the consumerist world we live in today, people spend too much of their time on what should be utterly trivial choices. If the state manufactured a single kind of toothpaste that it distributed to the whole populace (based on, say, what scientific research recommends is best for human teeth), that would be okay. It's not worth fighting over the right to pick Colgate over Crest. Or, at least, each individual has to make that determination for themselves.
Those human beings who opt to enhance themselves will be increasing both their freedom and their responsibility as they heighten their powers. But there is no need for everyone to have to do this. People should be able to legitimately opt out. Nonetheless, I will make arguments (such as I'm doing now) to encourage people to accept my positive understanding of freedom. But this positive freedom must be grounded in a widely-accepted form of negative freedom, in which the state "nudges" individuals in certain directions (based on evidence obtained from science and other sorts of human inquiry), but ultimately gives people the option to opt out. So long as I do not pose a significant threat to the freedom or well-being of others, I ought to be allowed legally to make any choice I desire about the character and circumstances of my life.
The issue is maximizing freedom. Individual choice provides us with a conception of freedom thin enough to be minimally coercive (one of the few things it prohibits is the coercion of others), but thick enough to serve as a starting point for any further idea of freedom. Let people establish their own standards of freedom, or of any other values they wish. The key for us is to figure out ways to make all these different human possibilities "compossible", which is to say, mutually compatible. Trade-offs and tough decisions will have to be made, but if we use as a general guideline the maxim of choice maximization, then we have a political ideal that we can use to evaluate any future policy proposal. We must ask, "Will this allow and encourage individuals to be self-determining?" If yes, we move in the direction of a world of greater diversity and development. If no, then we risk creating new tyrannies to replace the old natural and traditional constraints that we have progressed so far in overcoming.
Omnilibertarianism is an elegant position, one that provides us with a simple measure for assessing progress in the world. Things will be lost in the transition to adulthood. The humans who exists hundreds of years from now may look nothing like us, they may not even be biological. But they will still be us, they will still embody that quality which I would argue is most central to being human, being autonomous, self-determining, free beings. This quality must be preserved, or everything is lost. The reason is that it allows for the possibility of all other values. Creating values is what we do as humans, and the more individuals are pressured by circumstances into recognizing that, the more mature we can be as a species.
There are those who argue that "passivity", "randomness", some force or another beyond human control, is a necessary part of human identity. I for one do not see why we should be defined by our limitations when we could be determined by our positive capacities. There is no need to worry about an end to undergoing and suffering. These will always be with our species, because there are just some limits in nature that cannot be overcome. But this does not mean that we shouldn't try to narrow that realm as much as possible. Not leaving things to nature, but taking control and remaking it to satisfy our demands is precisely what it means to be a responsible moral agent. I'm fine with individuals refusing to take on this responsibility, but as a species, we must allow those of us who want to go beyond, who want to redesign nature (beginning with their own individual nature), to do so. Otherwise, we end up deciding for the rest of humanity that they cannot be free. It is not our right to make such a decision for others.
I now see that it is my purpose in life to show people the superiority of this view, and to try as far as possible to implement it. Radical changes are in our future, but so long as we do not forget the importance of freedom as individual choice, we will never lose the most important aspect of our humanity. We may become more than human, but that is not the same thing as inhuman.
In a sense, I am making a plea to the world. Let me determine my own destiny! Let all people have such power, as far as is possible. It's fine to try to convince people of your ideas (and there are going to have to be some things that we all agree on, namely, the conditions for allowing further possible freedom), but we cannot use the tool of the law to impose one set of values on an entire society. Let as many values flourish simultaneously as can be! This is itself a value, but it is an enabling value, valuable precisely because of what it allows. Value is itself valuable.
In a way, I must admit that I am influenced by Leibniz's idea of the best of all possible worlds. He thinks that such a world has a minimum of principles, but a maximum of diversity of expression of those principles. I disagree with him, because I think such a world is not given, but will have to be a human accomplishment. We are the only intelligent designers in the universe (that we know of). Let's not run from that. Let's make this world the best it can be.