The span of life

Abstract

1. This paper originated with a sense of irritation at the way in which the graduation of age rates of mortality has become more and more complicated by the apparent determination to assume some underlying law of mortality, a law which could not possibly be deduced from observations in the past or present man-made conditions of dangerous living. It then developed into a consideration of graduation from a less frequently adopted point of view, i.e. a look at the distribution of lengths of life (the so-called curve of deaths). This led inevitably to a review of the long-pursued controversy as to whether or not there is a predetermined biological maximum to the human lifespan under ideal conditions and beyond that to a review of the biological evidence for this maximum and the possibility of extension by environmental or medical intervention. Finally, this led to the likely results of such environmental and medical advances and to some experiments in mortality projection.