EVOLUTION AND DISEASE. 
INTRODUCTION. 
Most persons believe Pathology, as the Science of 
Disease is called, to be so outside the comprehension 
of ordinary individuals, and even in its general bearings 
so utterly devoid of interest to all but medical men, that 
much misconception prevails in the minds of even 
educated persons in regard to its fundamental principles. 
As a matter of fact Pathology is only a department of 
Biology, and it is very important to bear this in mind if 
we wish to study successfully the origin, cause, and 
spread of disease. Yet paradoxical as it seems, whilst so 
many regard Pathology as occupying an isolated position 
among sciences, medical writers always point out the 
difficulty they find in framing a definition of disease, and 
indeed the impossibility of stating where health ends and 
disease begins. 
It is not my object in the present work to attempt the 
framing of a definition of disease, or even to offer a 
suggestion as to the borderland between it and health. 
This difficulty is frequently illustrated in a striking 
manner in a law court; it is not uncommon for a judge 
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