Ayahuasquero don Juan Tangoa Paima claims that he can heal cancer, AIDS, epilepsy, heart disease, stomach and intestinal conditions, sexually transmitted diseases, depression, drug addiction, mental disorders, migraines, anxiety, and obesity — indeed, he offers the “complete and total healing of any and all afflictions.”

Now, these are staggering claims. If don Juan can do even a tiny part of what he claims — cure breast cancer, for example — then by all rights he should be an immensely wealthy man, teaching his techniques at major hospitals and medical schools. Of course, the term healing is ambiguous. Does he mean by the word heal the same thing that, say, a clinical oncologist means by it? If he means something different, then perhaps in this context it would be fair to make that clear.

So perhaps we can simplify these claims by asking a straightforward question. Can don Juan heal periodontal disease?

There are several overlapping ways in which people in the Upper Amazon categorize sickness. Some sicknesses are considered to be natural, God-given, a curse of God. Such natural sicknesses respond to store-bought medicine, antibiotics, injections, and hospital treatment; they do not require — or do not respond to — the intervention of a shaman.

Now, there is not a lot of agreement as to what sicknesses fall into this category. Generally, natural sicknesses include colds, sore throats, skin infections, malaria, parasites. Shuar shaman Alejandro Tsakím Suánua refers eye problems, amoebas, infections, and cataracts to a biomedical physican; mestizo shaman don Agustin Rivas refers any sickness caused by microbes or requiring surgery; my teacher don Roberto Acho refers cases of stroke and cancer. Among the Shuar, natural sicknesses include those associated with white people, such as cholera.

But accidents — falls, snakebites, a tree falling on someone, someone badly cut with a machete — are not natural. And some sicknesses are noticeably odd from the outset: the symptoms begin suddenly, the pain is focused and affects a particular part of the body, the patient deteriorates rapidly, there are bad dreams, there are inscrutable changes in bodily function and affective states, and the instruments of western medicine are unavailing. In such a case, the sickness is not natural, but has been inflicted by a person — a brujo, sorcerer, or an enemy employing any of several well-known forms of folk magic. Such sicknesses are caused, not by microbes, but by a failure of right relationship with a human being. Alejandro Tsakím calls such sicknesses, induced by human sorcery, wicked sicknesses.

Sometimes these wicked sicknesses overlap with biomedical diagnoses. My teacher doña María Tuesta suffered what the biomedical doctors in Iquitos called a massive stroke, from which she eventually died; yet many of her friends claimed that she was in fact the victim of virotes, magical darts, projected into her body by a specific person, a brujo, for reasons of greed and resentment. It is in this sense, perhaps, that don Agustin Rivas considers cancer, heart attacks, and ulcers to be — at least sometimes — capable of shamanic healing.

Here is a story. I was sitting with my teacher don Roberto late one night when a canoe pulled up on the riverbank. A man half-carried another up to the house, asking for help: his cousin was very sick, he said, with pains in the belly. Don Roberto performed the foundational healing triad of mestizo shamanism — shacapar, rattling; chupar, sucking; and soplar, blowing tobacco smoke. I sat there thinking: Omigod, what if this man has appendicitis? I asked don Roberto and the man himself if I could touch him. No fever. I gently pressed his abdomen: no rebound tenderness or guarding; no pain on the right side when pressing on the left; nothing special in the lower right quadrant. Whew.

But this simply postponed the real question. Do I believe that don Roberto can heal acute appendicitis?