hen they seek to determine someone’s cause of death, doctors often speak of “organ failure” – the failure of an essential system in the body (cardiovascular, renal, etc.) – or even of “multiple organ failure” – the loss of function of two or more such systems. No matter how old one is, one never dies of old age (technically, age cannot by itself be the cause of death), but because of some failure that takes place within the body. Such language is revealing. It suggests an unspoken, perhaps unconscious belief that our organs are meant to work indefinitely, and, by implication, that we are supposed to last indefinitely as well. We – this line of thinking goes – are not “exhaustible” (meant to burn for a while and then flicker away), but designed to live forever. Should we somehow manage to find better parts, or more expert maintenance, our mortality problem would be all but solved. It is largely such a belief that