Over the decades to come we will become an immortal species. Immortality is a word somewhat degraded from its old absolute meanings, and now people tend to use it as a lazy shorthand for an end to degenerative aging and disease achieved through medical science, such that no-one will grow frail or die. In that sense immortality means a life expectancy of about a thousand years or so given today's accident rates, but there is no reason to expect those rates to stay the same. Imagine every science fiction technology that might possibly be developed over the next few centuries, all of which will be applied to reduce the risk of injury and accident in everyday life. That will happen. It won't stop there, of course. A life expectancy of millions of years, involving a transition to become something far larger and more resilient than the present human form, existing as a distributed machine entity that can shrug off local supernovae as a passing inconvenience - well, that also is on the cards. Someone alive today will do that or something similar: all it takes is for that person to live sufficiently far into the decades ahead to enter the time in which medical advances increase future life expectancy faster than aging eats it away.
The big deal in today's advocacy is to help determine whether it is plausible to talk about people in middle age reaching that upward curve of life expectancy versus today's newborns. That latter demographic are, I think, almost certainly going to benefit from a life no longer limited by aging. They have time to wait out half a century of technological development at today's breakneck pace. It seems unlikely that they will miss out. The point of advocacy is to speed up what is inevitable for the 2060s and make a reality for the 2030s, as that is by no means a sure thing. There are all too many examples in the past of technological innovators and early advances making their mark and setting out the foundations of their field, only for it to take decades for interest to grow to the point of widespread development and availability.
Immortality as a term is often used to mock people who aim to speed progress towards even modestly extended life spans, attained through advances in medicine. This is somewhat interesting given modern cultural relationships with death. We have become a society that hides the ugly reality of the end of life behind curtains. It is the thing not shown, not talked about. I was struck by this comment from a writer who attained some popularity a little while back:
"We're seeing death in a new way. Instead of taking it for granted, the people I know see it as a personal catastrophe. I get emails from people who are actually surprised that someone has died. They regard it as an injustice. I understand their feelings, I get it, but this is a fairly new perspective on death. Nobody in the 1900s would have regarded death as a personal catastrophe. They would have mourned and might have been grief-stricken, but they saw death all around them."
This is another part of the strange puzzle that is the indifference and even hostility of the public at large towards efforts to treat aging as a disease and thus extend healthy life: (a) few people acknowledge death and aging in the same way as was the case in the past, (b) yet billions are spent on obviously fake ways to obscure the cosmetic consequences of aging, or to try to slow its progression, and (c) at the same time all sorts of accusations are thrown at those who are engaged in serious scientific work to actually slow or reverse aging, while (d) people are largely supportive of efforts to treat specific conditions that are caused by aging, such as cancer and Alzheimer's disease. I have always found this mix of views and opinions, often all held at the same time by a single individual, to be mystifying.
One of the ways in which people reject even the possibility of modest life extension is to talk about how bored they would be, and how terrible it is to be alive and bored versus dead. After ten years of following progress in longevity science and advocacy for longer healthy lives it remains unclear to me just how much of that is a matter of rolling out any old argument to justify a predetermined position of opposition, the pro-aging trance as Aubrey de Grey has it, versus it being an actual heartfelt belief in the endless dull grey doldrums that await should anyone dare set foot past their 120th year of life. Like many of the arguments against treating aging as a disease and extending healthy lives as far as possible as quickly as possible, it doesn't stand up to even a cursory logical examination. In all probability it is not meant to - that isn't the point.
Categorical desires are more significant desires. They are akin to life projects or plans. They are desires around which our self-worth is organised, e.g. the desire to write a great novel, raise happy and successful children, make important scientific discoveries, and so forth. Williams claims that the satisfaction of contingent desires, while important, is not really what makes life worth living. It is the satisfaction of categorical desires that does that. Since they are the focal point of what we do on a daily basis, it is their satisfaction that makes us want to live. Williams's worry is that there are only so many categorical desires that one self can pursue. In the course of an immortal life, you would end up pursuing and satisfying every achievable categorical desire. Eventually, you would have nothing left to make your life worth living. You would be bored, listless and tired of life.
Which all seems pretty silly to be concerned about to me. Boredom is a high class problem to have in comparison to pain, frailty, and the drawn-out death of everyone you care about. First things first: make the world a better place incrementally, and don't try to pretend that arm-waving about mental states in as yet hypothetical futures are in any way important in comparison to the prevention of suffering and death today.