ALEX COMFORT 
likely pattern for us to achieve. More probably we might find 
means of prolonging the period of adult vigour, either alone, 
or with proportional prolongation of the pre-adult and the 
senile stages—a scalar expansion of our present survival 
pattern. Finally, and perhaps least profitably it might be 
possible to prolong the total duration of life only by prolonging 
the stages prior to maturity. This seems to be the nature of the 
effect observed in the rats McCay used. Its utility in man would 
depend entirely on how late in the process of development it 
could be made to operate. There would be little point in 
interpolating five or ten years at a physical and mental age of 
twelve, except perhaps to make a longer period of pre-adult 
training possible. If there were any way of stopping or slowing 
the clock at a later age, that would represent a more significant 
achievement—a marking-time for, say, five years at the 
apparent age of twenty or thirty, after which bonus we should 
complete a normal life-cycle. Of all the possible modifications 
which the system childhood-adulthood-senescence could under- 
go, this comes nearest to the aims of von Boerhaave’s alchemist, 
leaving aside the reversal of established senility, and it seems the 
most socially desirable. At the moment it is possible to produce 
this result experimentally in fish, which respond to dietary 
retardation not by remaining immature but by failing to increase 
in size. Or the rate of scientific progress in the prolongation of 
life might conceivably become such that provided one was 
young enough for treatment, one might hope for a series of such 
bonuses, as many patients with incurable diseases today have 
some reason to expect that the rate of progress in medicine may 
be quick enough to save them. There is only one reason for 
mentioning this possibility, and that is this: the psychological 
effect of anything which rendered the prospect of individual 
survival “‘open ended’’, even if the real gain in years were not 
great, could, I think, be extremely profound. The knowledge of 
our fixed fiespaa an idea we verbalize quite freely but do 
not usually admit fully to consciousness—may we play 
a much bigger part in our emotional life than we realize; it is 
one of the earliest unpleasant intellectual discoveries oa 
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