Fear can originate with mind. Fear produces fear. Fear disarranges circulation of the blood and the nourishment of muscle and nerve. Fear can produce many bodily disorders which in turn feed fear. Fear cannot last unless bodily symptoms exist or arise to justify and feed it. Fear can be cured and removed in two ways: (1) by driving away fear and releasing bodily disorders from its thraldom; (2) by removing the disorders and making fear impossible to the logical mind. An enforced sea voyage begins with the disorder; a clever, buoyant physician begins with the fear. Patent-medicine proprietors, quacks, and fakes of every kind begin by displacing the fear with hope or cheer; the physical disorders frequently vanish by the same window as fear. For _fear_ write _self-pity_, _morbid self-consciousness_, _hypertrophied submission_; to _hope_ and _cheer_ add _smile_, _relaxation_, and _zest_; and we have the chief elements of mental hygiene and the reason why intelligent as well as unintelligent men like to be swindled by medical or other quacks. The social aspects of mental hygiene are particularly important. Once admitting the power of the mind to decrease vitality, we recognize the duty of seeming happy, buoyant, cheerful, vital, at least when with others, for the sake of others' minds and bodies. Secondly, we find the duty to refrain from commenting on others' appearance in a way that will start "ingrowing thoughts." A "grouchy" foreman can give blues and indigestion to a roomful of factory girls. A self-pitying teacher can check the heart beats of her class, cause arteries and lungs to contract, and deprive the brain of fresh blood. An oversympathetic neighbor can put a strong man to bed by discovering signs of nervous disintegration. Shall we gradually work out a code of mental hygiene rights and nuisances that will require compulsory notification of the "blues" and compulsory segregation of every person unable to "smile dull care away"? Is the time coming when boards of health will accompany infection leaflets with messages such as this from James Whitcomb Riley: Talk health. The dreary, never-changing tale Of mortal maladies is worn and stale. You cannot charm or interest or please By harping on that minor chord, disease. "Whatever the weather may be," says he, "Whatever the weather may be, It's the songs ye sing, and the smiles ye wear, That's a-making the sun shine everywhere." Mental hygiene has hitherto enjoyed an evil reputation and has been condemned to generally evil associations, because the rank and file have been ignorant of hygiene of every kind. Medical science has so long enveloped itself in mystery that it is in danger now of becoming discredited and of falling heir to the mantle of quackery.