When we talk about life extension, we mean people living much longer than they do now, and, more importantly, people who are healthier for longer. For example, we mean being 120 with the health of a 30-year-old. Hang on, though — hasn’t a person who is 120 years old already more than lived their life? Hasn’t that person’s time more than come?

News flash: you haven’t lived your life until you’re dead, and even then, you might not necessarily have crossed off all the items on your list. So, no, there is no such thing as an age when you have, by definition, “already lived your life” — not 80, 90, 100, nor any other. What people actually mean when they say that someone has “already lived their life” is that, in their opinion, that person has lived long enough, and thus he or she might as well, and perhaps even should, die.

People who, for one reason or another, fear a world without aging tend to say things like that. Personally, I am much more afraid of a world where other people get to tell you when your life has been long enough, and, consequently, I tend to say that the only one who should have the right to decide when you’ve lived long enough, if ever, is you — not other people, not nature, not an imaginary greater good. You.

However, I don’t think that these people just like telling others how long they should live; rather, it is my opinion that they fall prey to a common misconception, which I like to call the misconception of the two deaths.

One death to rule them all

How many kinds of death are there? Well, as a first approximation, you might be tempted to answer “two”; there is death by old age, and then there are other causes. (In case you’re wondering, these are exactly the two deaths that give the misconception its name, so, as you might guess, this answer is wrong.) Then, if one wants to be pedantic, one could start listing examples of the other causes, and thus the answer might easily become “many”. This is wrong too, by the way.

The correct answer is one. There is only one kind of death, namely death by “something essential in your body stopped working.” Then, of course, we can go into details, such as what specifically stopped working and why, but they’re indeed just details, useful mainly to any doctors who were trying to prevent your death or to the coroner to write on your death certificate.

Let me give you an example. Suppose I got shot in the heart. (Hopefully that won’t happen.) What killed me would be the fact my heart stopped; in turn, what caused my heart to stop was the bleeding hole that the gunshot punched into it. Similarly, if I died of a heart attack, the cause of death would still be that my heart stopped, but what caused it to stop would be something else — probably, I read a pro-aging article or something like that.

So, when people say that someone has died of old age, they’re just using shorthand to say that something essential in that person’s body stopped working, and the cause of that failure was something that has a higher likelihood to happen to you past age 70 or so.

Five wrong reasons

What does this have to do with the whole issue of whether somebody has already lived their life or not? In my opinion — and, mind you, it’s just my opinion that we’re talking about — it has everything to do with it. I think that many people assume that all the deaths in the “other causes” category are not okay in the sense that, when you die of one of those, you have not yet lived your life; conversely, when you die of old age, they think you have. Probably, it’s because they think that the so-called death by old age:

happens of its own accord, without external intervention; lets you live for as long as “naturally” possible; generally allows sufficient time for you to do all that is considered standard for human life (study, work, have a family, etc.); occurs at a point when you’re generally not healthy enough to do much else; is inevitable, which adds to the feeling that this is how it ought to be.

Point number one is only partially true. Sure enough, even with the healthiest of lifestyles, human genetics is such that you can’t really hope to live much more than 120 years (without more radical interventions, such as rejuvenation biotech). However, sufficiently unhealthy lifestyles can make the very same diseases of old age happen sooner. This means that the way you live your life affects how long your life will be; therefore, it’s not true that death by old age only happens of its own accord. Your external interventions, even something as relatively trivial as what you eat, can and do make a difference.

Consequently, point number two is not true. Even without opening the worm can of the meaning of “natural”, since the age at which the diseases of aging strike (and thus kill) you is influenced by your actions, it is by no means guaranteed that you couldn’t have lived longer than you did if only you had made different lifestyle choices, even something as simple as eating in a more healthy way.

Points three and four are the truly interesting ones here. Currently, the life of an average human entails a number of standard milestones whose achievement pretty much defines how much of a successful, or at least “normal”, life one has lived. We’re talking mainly about studying, having a career, starting a family, perhaps becoming good at any hobbies you might have, having grandkids, and then “enjoying” your “golden years”.

These milestones dictate the rhythm of our lives to such an extent that not only do people cast suspicious glances at you when you fail to deliver on schedule (“You’re thirty already; when are you going to have kids?”, “Isn’t it about time you settled down and had a career?”, etc); but also, most people think that, once these goals are accomplished, there wouldn’t be much else to look forward to even if you were healthy enough to accomplish more, and as per point four, you’re not anyway.

These two points are pretty much the very essence of this whole “having already lived one’s life” thing; past the standard milestones, there isn’t anything else worth doing, and even if there was, you’re in no condition to do it. Hence, you’ve pretty much already lived your life. One might even think that human lifespan is just long enough to let us do precisely all we want or need to do.

This is completely backwards, of course. Human lifespan didn’t stretch and shrink just enough to perfectly accommodate our favourite milestones. Rather, we adapted to our lifespan, planning and scheduling our lives, our societies, and our policies around our biological limitations. Our standard milestones and their chronological progression are a consequence of our average healthspan and lifespan, not vice versa. The “normal” course of life outlined above is by no means the right one, better than others, or what ought to be. It’s just all we could afford under the circumstances. For some people, it might be enough; for others, it might be terribly insufficient. However, I do think that, given the option, many people who profess their satisfaction with the current state of affairs might seriously reconsider.

This brings us to point five, which, up until this moment in history, has made the whole discussion moot; whether it occurs sooner or later, death by old age is inevitable. So, not only is there little point discussing ifs and buts, but maybe, if things stand the way they do, there’s a good reason. Isn’t it comforting to think that, if we’re all doomed to die, there’s a good reason why this is so? Pretty much the way that a fervent believer may not understand why God let so many innocents die in a terrorist attack, or a war, or a catastrophe, but is relieved to think He must have had a good reason to do so, many people think old age comes to take us away for some higher purpose — preventing overpopulation, boredom, or whatever.

With the advent of pioneering rejuvenation biotechnology, the inevitability paradigm of point five is starting to crack, and as it will become clearer and clearer that defeating aging is possible, I argue that many people will do away with the idea that if aging exists, then it ought to, without even bothering going through the (obvious) reasons why this idea is fallacious. The previous four points, as we’ve seen, rest on seriously shaky grounds, and taken all together, these points don’t make death by old age any more acceptable than any other kind of death, and don’t mean in any way that when you die of aging, you had already lived your life and couldn’t — or shouldn’t — ask for more.

Who knows; maybe, there will come a point when you’ve already lived your life. However, when that point is, and whether and how your life should end, I think should be only in your hands.