People believe in infectious and contagious diseases, [30]

and that any one is liable to have them under certain [1]

predisposing or exciting causes. This mental state pre-

pares one to have any disease whenever there appear the

circumstances which he believes produce it. If he believed

as sincerely that health is catching when exposed to con- [5]

tact with healthy people, he would catch their state of

feeling quite as surely and with better effect than he does

the sick man's.

If only the people would believe that good is more