Any one ailment has a far-reaching effect throughout the system. It is
because of this far-reaching effect that the 'one idea' specialist in
medicine has so often thought his particular specialty to be the one and
only gateway to all therapeutics and hygiene. The oculist is liable to
look at all ailments as related to the eyes; the dentist as related to
the teeth; the mental hygienist as related to wrong attitudes of mind.
If we examine their claims, we find that they are usually right in their
affirmations, though wrong in their denials. It is their affirmations in
which we are here interested. They find that the ailments within their
own special province extend in unsuspected ways, and to a surprising
degree into seemingly remote fields; and that to remedy the special
defect which they can treat, will often go a long way toward remedying
numerous other ailments.