GENERAL INTRODUCTION
1. Greek Medicine and Hippocrates
WE have learned to associate, almost by instinct,
the science of medicine with bacteria, with chemistry,
with clinical thermometers, disinfectants, and all the
apparatus of careful nursing. All such associations,
if we wish even dimly to appreciate the work of
Hippocrates and of his predecessors, we must endeavour
to break ; we must unthink the greater part
of those habits of thought which education has made
second nature. The Greek knew that there were
certain collections of morbid phenomena which he
called diseases ; that these diseases normally ran a
certain course ; that their origin was not unconnected
with geographical and atmospheric environment ;
that the patient, in order to recover his health, must
modify his ordinary mode of living. Beyond this he
knew, and could know, nothing, and was compelled
to fill up the blanks in his knowledge by having
recourse to conjecture and hypothesis. In doing so
he was obeying a human instinct which assures us
that progress requires the use of stop-gaps where
complete and accurate knowledge is unattainable,
and that a working hypothesis, although wrong, is
better than no hypothesis at all. System, an organized
scheme, is of greater value than chaos. Yet
however healthy such an instinct may be, it has
