As the joke goes, taxes and death are inevitable, but death at least does not become worse every time the U.S. Congress is in session. Taxes are a separate topic; here, only death will be discussed. The first question is obvious: Is death really inevitable? If this is the case, there is obviously nothing to discuss.

Actually, however, immortality does not contradict any known law of nature. Life, in general, is the exchange of matter, energy, and information with the environment. The only requirement for this exchange to occur is the difference of potentials. The absence of such difference results in entropy, or “thermal death”—or, for live organisms, just death. But it is not inevitable. Cells multiply via mitosis, which makes their material practically immortal. It follows that difference of potentials disappears (and death occurs) due to some nonfundamental factors.

These factors were obviously developed by biological evolution. Life adapts to changes in the environment by mutations. But the population of any species is limited by the chains of food. The presence of older generations would automatically bring down the percentage of the younger one—and, therefore, the chance of some mutants to fit the environment. Species that suffered from this disadvantage died out. Genetically programmed death is the tool of species’ survival.

Homo sapiens obeyed the same rules—but eventually, their survival became less dependent upon genetic programing and more so upon accumulated knowledge. Our smart ancestors found out that these old and useless members, who could not even hunt, were also a source of priceless knowledge. Longevity, the first step toward immortality, became the tool of survival. Elderly knowledge keepers, respected and fed by the tribe, were the oldest professionals.

It follows that neither death nor longevity (and, by extension, immortality) can be by itself bad or good. Their role as tools of species’ (including humans) survival determines it. Today, biological evolution does not affect us anymore, and knowledge is accumulated outside the human brain. Longevity has become, rather, a personal problem addressed by healthy lifestyles, progress in medicine, genetic engineering, and so on. Eventually, we will be able to defuse genetic time bombs and shift immortality from the domain of science fiction to one of reality.

But should we? From the very beginning, cheating death caused inequality and suspicion. Elderly knowledge-keepers were fed and cared for—but the rest of the tribe was not. Later, costly medical help was reserved for those who could afford it: rulers, the privileged classes, or simply the rich. Medical practitioners guarded the source of their wealth. Contrary to common understanding, the guild administered the famous Hippocratic oath, first of all, to prevent special knowledge from being leaked to the uninitiated. During a million years or so, human population grew from its biological limit of less than 100 million to just 500 million in 1650. And then it exploded: 2.5 billion in 1950; 5.3 billion in 1990; and it continues to grow exponentially. Superimpose ever-growing longevity—and the question becomes obvious: Is this exponent sustainable? And even if yes, is it desirable?

Economy is the only way to support that exponent. In essence, it applies labor to natural resources, thus transforming them into something satisfying our needs. Labor productivity (more accurately, “surplus product,” or whatever is left after the laborer’s own needs are satisfied) supports socioeconomic progress, which, in turn, increases productivity. This mutual reinforcing (known in cybernetics as “positive feedback”), which is the first of two prerequisites for the exponential growth of human population, has of course no natural limits. But the availability of natural resources, which is the second prerequisite, does impose limits. Earth can provide only so much living space, water, minerals, organic matter, and so on. Sooner or later, colonization of the solar system will become humanity’s only alternative to ending up as Earth’s inmates.

And this is where longevity might help. Despite all the wars and lesser conflicts, all of us are still inhabitants of the same planet. We travel to other countries and have friends or relatives there. We exchange goods, knowledge, and masterpieces of culture. We need each other. But all of that is only possible because human longevity is much greater than the time required for these activities. For live contacts of Earth with its distant colonies, travel time would exceed people’s current life spans, which would make them difficult if not impossible. With a life expectancy of 120 to 150 years, frequent interplanetary travels would become rather the norm.

The time might therefore come—and maybe sooner than we think—for longevity to become a necessary tool to fight another barrier, this of Earth’s limitations. Necessity, it was said, is the mother of invention. In this case, we must find ways to expand longevity.

Immortality, or at least super-long life that resembles it, might eventually become not just tolerable or even desirable but vitally necessary. The solar system is not limitless, either. The long journey of humanity began with breaking the barriers of its natural bio-niche. Then it broke many other barriers. This is the only alternative to entropy. If we leave hyper-spatial travel to science fiction, this can be achieved by cryogenics or maybe by sending out asteroid-size spaceships. Descendants of the first astronauts will reach the stars; their descendants will return with a priceless cargo of knowledge.

Or they may not return at all. What need would they have for that ancient, overcrowded Earth? Such travel would not solve the population problem. A few might prefer a life sentence in a galactic ship to remaining on Earth, however overcrowded. Near-immortality would become humanity’s only tool of survival. It would turn that life sentence into an exodus, allowing people themselves—not only their descendants—to break the last barrier: discover, terraform, and populate new planets across the universe. They could meet our sentient brothers while still remaining close to their earthly ones, whom, if they wished, they could easily visit during their long lives.

But why bother? After all, people might prefer problem-free, hedonistic lives as a reward for a million years of hardships and suffering. Robots would take care of all their material needs. Sounds nice—except the human race would be degraded to the fate of pampered pets or dolls. Works by H. G. Wells and Isaac Asimov proved it indisputably. For our survival as human beings, there is simply no alternative to breaking barriers and, therefore, creating the necessary tools to accomplish it—including super-longevity. There are hardly any shortcuts on the journey; that’s why this is not a matter of personal choice. Humanity must begin that journey as soon as possible. If you are not convinced, let us meet in a couple of centuries and see what happened.