The hydra is a freshwater animal, just a few millimeters long. It acts like an upside-down sedentary jellyfish, collecting food with tentacles. The creature is especially interesting in this: It seems to be immortal. Because the hydra reproduces by budding rather than mating, it uses its stem cells to regenerate aging tissue. Scientists have discovered that the same gene responsible for the hydra's continual use of stem cells could allow human bodies to better repair themselves and potentially live healthier and longer.
The discovery is only the latest scientific breakthrough to make very real the possibility that we will, sooner or later, extend the human life span.
But should we? Gilbert Meilaender, a professor of theology at Valparaiso University and former member of the President's Council on Bioethics, takes up this question in Should We Live Forever? The Ethical Ambiguities of Aging (Eerdmans). At a time when millions die without access to basic medical care, extending the life span of a few might seem morally dubious. But Meilaender leaves aside many related ethical questions, such as the problem of ensuring equitable access, for rich and poor alike, to these prospective fountains of youth. Instead, he zeroes in on the issue of whether, in and of itself, it would be good to pursue longer life.
Meilaender doesn't categorically reject extending life. If life is good, he argues, it very well may be good to have more of it. But there are costs, and that is the crux of the dilemma.
By seeking more life, we change what a human life is, and inevitably lose aspects that make it desirable. There is especially a tradeoff between life extension and reproduction. One life extension method—calorie ...