If you don't like what the experts are saying about AIDS and HIV, about causes and effects, just wait a minute and you'll hear something else.
AIDS confounds us. In the wake of the summer's political conventions and the Amsterdam, Holland, AIDS conference, convenient ways of thinking about the disease are again cast into doubt. Does HIV, the human immunodeficiency virus, ''cause'' acquired immune deficiency syndrome? What about the dozen or so recently described cases of the syndrome without evidence of HIV infection? Does anal sex ''cause'' AIDS? What about the dramatic upsurge in cases among women and, more generally, among AIDS patients' heterosexual partners?
Patients with AIDS -- with almost any illness -- understandably want answers to twin questions: ''What's causing this thing?'' and ''How is it going to play out?'' In the current AIDS epidemic, these questions of causation and prognosis have become vexed ones. Especially in the matter of cause, there is bitter debate.
That's what I see as a physician.
As a historian of medicine, I look at the welter of controversies surrounding the HIV epidemic, and it seems thoroughly familiar. All sides appear to suffer from a case of acute history deprivation.
What is the ''cause'' of AIDS? The quest for an answer has been the occasion for much ink shed, with at least three camps more or less established:
* The narrow or ''condensed'' view, probably representing the majority of scientists, attributes AIDS to one or more retroviruses and explains seeming anomalies in disease patterns by citing the unusual immunologic injury brought about by those viruses.
* A middle-ground position accepts HIV as the primary cause of AIDS but postulates a variety of chemical, microbiological or even environmental ''co-factors'' that greatly affect the course of the disease.
* A behavioral or ''expanded'' view, espoused by a small number of investigators who suggest that HIV, or in fact any virus, has little or nothing to do with AIDS: that it is more likely ''caused'' by damaging behaviors, especially drug-taking, thus discounting the likelihood of its spread to clean-living heterosexuals.
None of this is surprising. In the manner of ritual incantation, if we can just come up with the right explanatory framework, if we can just properly ''know'' what causes the disease, then maybe we can make ourselves proof against its onslaught. Our basis for understanding AIDS and its root causes also has enormous social, political and economic ramifications.
Every epidemic (even in our own time: Remember legionnaires' disease? Toxic shock syndrome?) has become the focal point around which factions have squared off, each propounding a pet theory of causation. Find the causal ''agent,'' and you've found, more often than not, the likely remedy. And therein lies the rub. Unconsciously, we reason backward.
He who favors one remedy will preferentially seek the ''cause'' that prompts it. If I believe that behavior change is the answer to HIV, I will gravitate to explanations that emphasize the role of behavior (say, drug-taking) as the primary ''cause'' of AIDS.
When we seek to understand what happens inside our own bodies, we scorn complexity and ambiguity. Consider: Is AIDS an acute illness or a chronic disease? The awkward answer, as was the case with the advent of syphilis in the early modern era, is of course both. Is it caused by bad germs or by bad character? Again, long after the germ theory of disease was in common parlance, there was still debate about some sexually transmitted diseases being punishment for ''bad'' behavior.
There was another variation on this theme in the last century. Acute illnesses such as cholera, as well as chronic ones such as tuberculosis, became politically charged crises around which raged fractious debate. Factions favoring the germ theory vied with sanitarians who at the time seemed more progressive as they pushed environmental cleanup. Later, at the turn of the century, it was still possible for experts to argue savagely about yellow fever. Was it caused by a bacterial organism? (Viruses were not yet known.) By mosquitoes? By swampy conditions? Their conclusions were consequential, with enormous repercussions on Western nations' economic welfare, the capability of armies and the expansion of empire. Others rushed to blame beriberi and pellagra on germs, ignoring the notion that something might be lacking in patients' diets.