If human being means something more than mere productive utility, then it must bear a goodness that develops with time and is therefore expressed in the elderly or nowhere at all. Traditional cultures do not see the elderly as burdens but as the fullest expression of the way of life of their City. The elderly possess an understanding of life and human nature, a wisdom, that can only come with age and experience; they are not a burden to the city but its greatest resource. We can always bear more young. A wise old man or woman can only be the result of many years of virtue and good fortune.
The Enlightenment cut wisdom down to what can be demonstrated via an abstract reason married to empirical observation. This had the immediate benefit of sweeping away many old and obstructive prejudices. But it also undermined any serious notion of wisdom, and specifically the conviction that there are important things about life and human nature that can only be known through long experience and reflection. The young Descartes could only choose to embark on his universal doubt if he thought that time and experience were not essential to any important truths. In the twentieth century, the young Albert Camus could write the following only in an intellectual universe thoroughly penetrated by the Enlightenment understanding of reason and its lack of respect for the wisdom that is a prerogative of age:
After so many centuries of inquiries, so many abdications among thinkers, we are well aware that this true for all our knowledge. With the exception of professional rationalists, today people despair of true knowledge. If the only history of human thought were to be written, it would have to be the history of its successive regrets and its impotences. (From the Myth of Sisyphus)
In the 12th century, someone who uttered such sentiments would be asked: What can a 29 year old possibly know? In the twentieth century, he is applauded for his bold vision.
We in the twenty-first century have difficulty finding reasons to keep the old folks around. We have eliminated the pursuit of wisdom as the goal of our universities; now we are contemplating severing our last link with the only people who might have finally learned wisdom on their own. What will happen to Athens when Socrates is given hemlock before he even has a chance to become the gadfly that wakes up the City?