ALEX COMFORT 
Contrary to what many of my own profession have believed, 
medicine is not increasing our lifespan, although it is making us 
live longer—nor is it likely to increase it in the foreseeable future 
by the techniques it now uses. What it is in fact doing todayis to 
ensure that a higher and higher proportion of those who are 
born alive realize that lifespan. This is being done in three 
ways: by reducing the accidental, non-age-dependent mortality 
from infections and deficiencies which would kill, or shorten 
further life, at any age; by reducing the level of what I may call 
environmental attack—it is less dangerous in many ways, 
though not in all ways, to live in a privileged community than 
in an Indian village or a Neapolitan slum; and by applying 
specific remedies to killing diseases in later life. A law of 
diminishing returns operates in purely palliative life preserva- 
tion, and at great ages cure of one disorder merely exposes, and 
sometimes aggravates, another—rather as replacement of a 
faulty component in an old radio may restore voltages to their 
correct original levels and blow out several other components 
which can no longer stand them. It seems quite certain that, 
failing a radical interference with the whole process of ageing, 
the prediction that medicine will give us 150 or 200-year life- 
spans, which was incautiously made by a number of nineteenth- 
century optimists, is wrong. The best we can hope from medi- 
cine and hygiene is that the histogram of lifespans will become 
increasingly Gaussian about a mode of, say, 75-80 years, and 
that its tail at early ages will shorten. 
Consider first the possibility of changes due to inadvertency. 
Most of those which one can foresee are likely to be adverse. 
Man has been killing himself prematurely for a long time by 
social, dietary, religious and political means. In general, these 
mischiefs are either semi-accidental in their age distribution, or 
are distributed along the vigour decline like other natural 
hazards. When wars used to be fought preferentially by and 
against young adult males, instead of against women and 
children, this arbitrarily affected the male survival curve. 
Motor-bicycle-riding still does so. The hazard of smoking is 
very similar actuarially to many cumulative industrial hazards 
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