Metchnikoff had the right attitude to the relationship between aging, health, and science - i.e. that we should treat it as a medical condition and work to fix it - but the misfortune to be born far too early for that goal to be practical.

Some of the International Longevity Alliance folk promote May 15th as Metchnikoff Day, a time to remind the rest of the world that we should be working to cure aging:

http://www.longevityforall.org/170th-anniversary-of-elie-met...

Metchnikoff wrote a short book entitled "The prolongation of life; optimistic studies", and it is well worth reading since it can be found online. He had very modern attitudes in this respect, and the debates he reports having with people around him vis a vis the desirability of treating aging as a medical condition are exactly the same as those occurring today.

http://archive.org/stream/prolongationofli00metciala/prolong...

How do we know that we are not too early, like Metchnikoff, or like the optimists of the 1970s? When it comes to our understanding of biochemistry and ability to manipulate our cells, we are as far beyond the 1970s as the 1970s were beyond the gentlemen-scientists working at the end of the 19th century. Why, however, is it different this time? Why are the seekers after agelessness now rational scientists rather than another crop of self-deluded fools or earnest workers overestimating the bounds of the possible? This is a question that crops up. I can recall numerous conversations over the years in which I was informed that someone knew an older fellow who was, back in the day, quite confident in the forthcoming existence of longevity-enhancing therapies, and yet where are those treatments decades later?

So why is it different this time? For one there is SENS, a detailed plan of development leading to rejuvenation treatments that could be prototyped in mice given a billion dollars and ten years, give or take. No such plan could have been formed a century ago, and while much of the basic knowledge that informs the SENS viewpoint of aging as an accumulation of cellular and molecular damage existed in the 1970s, SENS could not have been proposed as a serious project at that time even had someone had the realization. There was simply no way to even guess at how much time and money it would have required to build the tools to build the tools to develop the validation of the theories so as to build the tools to build the tools to develop the therapies, and so forth: it would have been a project on the scale of going to the moon, and with far less certainty of success.

More importantly none of the proposed paths to add decades or more of healthy life put forward in past generations, now obviously naive and wrong, were in any way rigorous or supported by large fractions of the scientific community. Only now do we have that, built on the vast body of knowledge of biology accumulated over the last century, and on the new tools of biotechnology of the past few decades. Only now are large numbers of scientists putting their careers and their reputations into the extension of healthy life. Only now do we have SENS approaches demonstrating life extension and improved health in mice, such as the senescent cell clearance studies published this year, and companies working on implementations.

Why is it different this time? The fact that funding for various scientific establishment efforts to extend life is growing rapidly. Most of these are in fact not going to move the needle all that much, but that isn't the point. The point is that the consensus in a significant fraction of the scientific community and its surrounding institutions of funding and review is that the time has come. Investment and interest in any given field are cyclic, and this present cycle will see billions poured into this field, and old narrow views of the implausibility of life extension swept away. Scientists are the arbiters of truth in our culture, though this is sometimes hard to see, and the rest of the world will follow their lead when deciding whether to take something seriously. That will create a feedback loop of funding and progress in which, yes, a lot of less useful work will thrive, but so will significant approaches such as SENS.

None of this was the case for past generations of what turned out to be deluded optimism. It is the case now. The times have changed, and it is different this time around.