Fool or a Physician

The writer who has used this expression is Dr. Cheyne, and he probably altered it from the alliterative form, "a man is a fool or a physician at forty," which I have frequently heard in various parts of England. Dr. Cheyne's words are: "I think every man is a fool or a physician at thirty years of age, (that is to say), by that time he ought to know his own constitution, and unless he is determined to live an intemperate and irregular life, I think he may by diet and regimen prevent or cure any *chronical* disease; but as to *acute* disorders no one who is not well acquainted with medicine sho…