Accompanying commentary relating to the paper of Peter Duesberg, Claus Köhnlein and David Rasnick: "The chemical bases of the various AIDS epidemics: recreational drugs, anti-viral chemotherapy and malnutrition". J. Biosci. 28: 383-412 (2003)

Björn Kralemann, Jochen Schaefer, Katrin Köther, Claas Lattmann

The International Institute for Theoretical Cardiology (IIfTC) was founded in 1983 to intensify the interest in the discussion and analysis of theoretical questions relevant to the development of health and medicine. A special aspect of this interest lies in the analysis and discussion of scientific controversies, the assumptions on which they are based as well as the manner in which such controversies are taking place. We advance as a frame work of such discussions the concepts of the Denkkollektiven (think collectives) developed by Ludwik Fleck and Thomas S. Kuhn. Fleck and later Kuhn argue that the development of Denkkollektiven forms a basis of scientific socialization and thereby also scientific controversies.

We are of the opinion that there are, indeed, non-scientific influences that act on scientific processes, which are in essence anti-scientific in nature yet can be observed rather frequently. They may impair and infringe upon the quality and the further development of scientific theories. In order to avoid such unfavourable influences, we have created a forum by the activity of our institute, so that the existence of such extra-scientific influences can be made an explicit topic of the discussion. Furthermore this forum is thought to guarantee that these scientific controversies are conducted matter-of-factly and are free from influences that do not belong into the scientific realm. Our position shall be substantiated in the following.

By giving a short outline of the general development and origin of scientific theories we want to show that the exclusion of alternative views from the mainstream research and scientific process removes important elements that are most essential for scientific progress. This process is characterized by continuously developing, criticising and revising hypotheses. Sometimes they can be called "scientific revolutions" (Kuhn) when they are thought to represent a change in paradigm and thus fundamental conceptual alterations in perspective. During such a process, assumptions must be discussed freely, revised and possibly be rejected. New ways of thinking have to be tested or the "right" questions have to be formulated and the relevant experiments have to be devised. This does not imply that any conceivable hypothesis should be considered as a serious candidate, but all hypotheses based on verifiable facts and observations must be considered, irrespective of their current popularity.

In sum, an effective scientific process can thus be characterized by the following criteria:

  1. to provide an as broad as possible fund of theoretical and methodical alternatives
  2. that compete with each other in a matter-of-factly argumentative discussion including all alternatives which are supported by empirical, reproducible data and can be connected with the respective theoretical state of the art of the science in question.
  3. The evaluation of the particular hypotheses in respect to their plausibility should be based on their scientific claim, on the agreement with the data, and on their abilities to explain and predict medical and scientific facts. Accordingly,
    1. a hypothesis has to be regarded as plausible to the extent that it agrees with empirical data and should be seen as non-plausible to the extent that it contradicts the data set;
    2. a hypothesis gains in plausibility to the extent that it is compatible with other scientific hypotheses and loses its plausibility to the same degree if it contradicts them without being able to explain the contradiction or reasonably questioning the contradicting hypotheses;
    3. a hypothesis gains in plausibility if it can explain relevant phenomena and their interconnections and loses in credibility if it is not able to make them understandable - or is even contradicting them respectively.

Elimination of reasonable hypotheses under other conditions is regarded as suppression of the scientific method and as an inhibitor of innovation.

An exemplary case for the attempt to eliminate and to suppress critical alternatives in thinking by using extra-scientific methods can be found in the history of the AIDS-research. Here, a situation has developed in the last 20 years that is violating the criteria of scientific rationality as they have been defined above. Briefly, the competing positions can be outlined as follows: The HIV-AIDS-hypothesis assumes that HIV is the sole cause of AIDS, and thus that AIDS is an infectious epidemic. By contrast, the paper by Duesberg et al. advances chemical causes - such as the consumption of drugs, anti-viral chemotherapy as well as malnutrition - as the causes of the various AIDS-epidemics and that HIV-infection plays no causal role. Whereas the HIV-AIDS-hypothesis is the widely accepted position, the position of the challengers is shared by only relatively few scientists. The fact that a majority faces a minority in regard to a scientific theory or facts or observations is not problematic at all, but is part of the scientific process. The problem resides in the manner and style in which the representatives of the majority are dealing with the position of the minority.

An influential article by John Maddox, the former editor of the journal Nature, is a perfect example of the behaviour we object to. In 1993 Maddox asked: "Has Duesberg a right of reply?" Maddox summarized his position as follows: "Dr. Peter Duesberg, the virologist-turned-campaigner, is wrongly using tendentious arguments to confuse understanding of AIDS and those in danger of contracting the disease. He should stop." Apparently, Maddox classifies a critical constructive scientific contribution by Duesberg as a campaign initiated against better knowledge to impede the scientific process and he thus denies Duesberg the right to openly express his opinion. Instead of dealing with the arguments put forward and of rejecting them on the basis of their theoretical inadequacy, he disputes the right of a scientist to participate in a scientific discourse. In order to maintain such a radical position, Maddox should have demonstrated unequivocally that Duesberg has left evidently and indisputably the ground of empirical science. According to point (3) of our position as outlined above, this would mean that Duesberg´s hypothesis does neither affirmatively or critically-constructively link up to the fund of knowledge of relevant theories in this field nor can be related to empirical data. But, first, Maddox´ mere supposition is quite remote from such a proof, and, second, the imputed facts are anything else than obvious. Thirdly, however, Duesberg´s et al. paper, which represents a summary of the positions that Duesberg has taken in the last years and can thus be regarded as the object of the polemics described by Maddox, demonstrates that the scientific standards as they have been defined above are exemplarily met. Moreover the polemics of Maddox are particularly astonishing since Duesberg enjoys a high international reputation as a cancer researcher - as has become quite evident in recent years by the great resonance that his theory of aneuploidy in the genesis of cancer has experienced. It would seem to be unlikely that the same person, who is highly respected in one field of science as a scientist par excellence, is suddenly not able to master the general rules and foundations of scientific methodology in another field of science.

With our present commentary on the paper of Duesberg, Koehnlein and Rasnick we do not want to argue which of the two positions that have been exposed above is the more plausible. This decision should be left to the judgement of the reader. Our goal is rather - contrary to the intention of the polemics that wish to prohibit alternative ways of thinking and discussion - to demonstrate that in this controversy there is indeed an important and serious problem of decision which every reasonable person should therefore make on the basis of scientific arguments. In addition it was our intent to show that independent of the question, whether Duesberg´s et al position will be proven correct or not, it does fulfil all criteria of excellent science in every respect.


Fleck, Ludwik, Entstehung und Entwicklung einer wissenschaftlichen Tatsache. Einführung in die Lehre vom Denkstil und Denkkollektiv, Suhrkamp Taschenbuch Wissenschaft, 3. Aufl., Frankfurt 1994.

Gibbs, W. Wayt, Untangling the Roots of Cancer, in: Scientific American, July 2003, 56-65.

Kuhn, Thomas S., The Structure of Scientific Revolutions, Sec. Edition, Enlarged, The University of Chicago Press 1970.

Maddox, J. (1993), Has Duesberg the right of reply? in: Nature, 363: 109.

Maddox, J. (1993), New-style abuse of press freedom, in: Nature, 366: 493-494.

Maddox, J. (1995), Duesberg and the new view of HIV, in: Nature, 373: 189.

Acknowledgements for valuable intellectual input: We express our thanks to Wolfgang Deppert and Günter Zick.

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