For this is the great error of our day in the treatment of the body: that the physicians separate the soul from the body. Plato It may be said of the concept of allergy— as Alfred North Whitehead, the late great mathematician and philosopher, once said of Christianity—that it has been a calamity. The good it has done (and, like Christianity, it has done a great deal of good) is sadly counterbalanced by the stultifying effect it has had on the treatment of disease. Because we have believed, as O'Leary said, we have stopped thinking, though it is to be feared that some of us who have disbelieved may have stopped thinking too, as Lobitz recently so engagingly pointed out.1 Most doctors today are committed by our heritage from the microbiologic period in medicine to a belief, in general, in a single pathogenic mechanism for a