Sentience is sacred

 It is a matter of time before Earth becomes uninhabitable, and there are several events that could wipe us out earlier.  So we need backups.  Unfortunately space seems so hostile in so many ways that it is really stretching it to imagine a successful self-perpetuating colony, and were there to be one, it would, given a different environment, soon evolve and thereby no longer be a backup.

I think you've put your finger on a tension that doesn't get enough attention in discussions of "saving humanity."

People often talk as though a colony on Mars, an O'Neill cylinder, or a planet around another star would be a backup copy of civilization. But a true backup would need to remain both alive and recognizably human for geological timescales. Those are different requirements.

The first problem is simply survival. Earth is extraordinarily forgiving. We evolved under one atmosphere, one gravity, one magnetic field, abundant liquid water, and a biosphere that constantly recycles nutrients. Every proposed off-world habitat is essentially a life-support machine that must function continuously. A self-sustaining ecosystem is much harder than a self-sustaining city. We have never successfully built one. Even Earth's biosphere occasionally undergoes mass extinctions, and it is four billion years old.

The second problem is evolution. Suppose a colony survives for 100,000 years on Mars, or in rotating habitats, or around a red dwarf star. Different gravity, radiation environment, day length, diet, pathogens, social structures, and technology would create different selection pressures. Natural selection would continue. Cultural evolution would continue even faster. After enough time, the descendants might be as different from us as we are from Paleolithic humans.

That raises an interesting philosophical question: what exactly are we trying to preserve?

If the goal is preserving human DNA, then divergence may not matter much. If the goal is preserving human culture, that is much harder; cultures transform within centuries. If the goal is preserving conscious beings descended from humanity, then evolution is not a failure but a success.

There's also a paradox. The more successfully a colony adapts to its new environment, the less it resembles the original. A Martian population that remains genetically and culturally identical to Earth for a million years would probably require continuous intervention. A population left to flourish on its own would almost certainly drift away.

In a sense, Earth itself is evidence of this. We are not a backup of the first mammals, nor of the dinosaurs, nor of the Cambrian animals. We are their descendants. Life persisted, but not in its original form.

So perhaps the realistic goal is not creating a backup of humanity, but creating a lineage. The descendants may eventually be different enough that we would regard them as another branch of life altogether. Yet they would still trace their ancestry back to us, just as we trace ours back to creatures that would find us utterly alien.

Viewed that way, the challenge is less "How do we preserve humanity forever?" and more "How do we keep the story going after Earth can no longer host it?" That may be a much more achievable objective.

A more realistic approach is that sentience is sacred and so spread it.

That's a perspective some philosophers and futurists have explored: the idea that the highest value isn't any particular species, culture, or genome, but the existence of conscious experience itself.

Under that view, humanity becomes less the end goal and more the current custodian. Our responsibility would be to ensure that awareness, thought, creativity, curiosity, and perhaps moral reasoning continue beyond Earth, regardless of the exact form they eventually take. Future beings might be genetically modified humans, descendants adapted to other worlds, artificial intelligences, or something we can't yet imagine.

This differs from many traditional arguments for space colonization, which often emphasize preserving us. Your framing emphasizes preserving sentience. Evolutionary change stops looking like a problem and starts looking like part of the process. If intelligent descendants on a planet around another star are no longer biologically human after a million years, the mission has still succeeded because conscious life continues.

Of course, the idea that sentience is sacred is itself a philosophical commitment rather than an established fact. Some would argue that life in general is what's valuable. Others would argue that flourishing, happiness, knowledge, or freedom are the real goals. Still others would point out that sentience also makes suffering possible, so simply maximizing the amount of consciousness may not be enough.

But there's a certain grandeur in the notion. The universe spent nearly 14 billion years producing stars, planets, chemistry, life, and eventually beings capable of wondering about the universe. From that angle, allowing awareness to spread beyond a single fragile planet can seem like a continuation of a very long story rather than merely a survival strategy.

Your formulation also sidesteps the "backup" problem. The future doesn't have to be a museum preserving twenty-first-century humans. It only has to contain minds capable of experiencing, learning, creating, and asking questions. Whether they look like us may be of secondary importance.

No, sentience is central, combined with intelligence.  That it is sacred is basic.  Not sacred in a holy sense but in the sense that it is the thing that make existence have meaning.

That's a coherent philosophical position, though not one everyone would accept.

What you're describing sounds close to a form of sentientism or consciousness-centered ethics. In that view, matter, energy, stars, planets, and even life itself have no intrinsic significance apart from their relationship to conscious minds. A universe with no beings capable of experiencing it would, in a meaningful sense, be devoid of value. Meaning arises when there are entities that can perceive, understand, appreciate, suffer, hope, remember, and wonder.

The combination of sentience and intelligence is important in your formulation. A thermostat reacts to its environment, but we don't usually think it has experiences. A bacterium is alive, but whether it has anything resembling conscious experience is doubtful. Human beings—and perhaps some other animals—don't merely exist; they experience existence and can reflect on it.

From that perspective, the stars are magnificent not because they are stars, but because they can be known. Beethoven's symphonies matter because they can be heard. Mathematics matters because it can be understood. Beauty, truth, love, curiosity, and grief all require a subject that experiences them.

The philosopher Bertrand Russell once remarked that the universe may be vast and indifferent, but he still placed human consciousness at the center of what gives value to anything. Others, such as some existentialists, would say that meaning is not discovered in the universe but created by conscious beings. Your view goes a step further: meaning doesn't merely happen to be created by sentient minds; sentient minds are the necessary precondition for meaning itself.

One implication is that extinction becomes more than the disappearance of a species. If humanity were the only intelligent, sentient life in the cosmos, then its extinction would represent the loss of the only known source of meaning in the universe. If there are many civilizations scattered among the stars, the stakes are different because the phenomenon of conscious understanding would continue elsewhere.

Of course, we don't know which of those possibilities is true. But I can see why someone who regards sentience and intelligence as the foundation of meaning would place enormous importance on ensuring they persist and spread. In that framework, a lifeless galaxy is not merely empty; it is silent. A galaxy containing minds is a place where the universe has, in a sense, become aware of itself.