Cees Renckens, MD, PhD


Hoorn, Netherlands

“Evil can now no longer be perceived as just the lack of good (privatio boni),
but it demands recognition and legalization: that's new.” – Gerard Reve in
Book of Violet and Death

Cees N. M. Renckens, MD, PhD, has been a Dutch gynecologist since 1980 with Westfries Gasthuis in Hoorn (North Holland), with a special interest in infertility and endocrinology, retiring from active practice in June 2011. In 1988, Dr Renckens became chair of Vereniging tegen de Kwaksalverij, or VtdK — known in English as the Dutch Society Against Quackery. Founded in 1881, VtdK is the oldest anti-quackery organization in the world (note the term “quacksalver” in its Dutch name). Under his leadership, the organization grew from 300 to 2,000 members and Dr Renckens has made presentations all over the world. In 2006 he was appointed Knight of the Order of Orange Nassau for his work with VtdK in opposing many non-science-based health care practices. Under Dr Renckens leadership, VtdK won an important free speech legal case.

With many books and articles on quackery, mainly in Dutch, Dr Renckens has strongly argued that “alternative medicine” practices should not be the subject of research – that any “positive outcome must be considered an industrial accident.” He developed the “Dr. Renckens’s Quackiness Scoring System.”

After obtaining his medical degree in 1971 from the State University of Gröningen, Dr Renckens went on to work two years as a physician in Zambia at the Ndola Central Hospital, in its surgical and OB/GYN departments. Thereafter, he specialized in OB/GYN in Amsterdam University’s hospital. His special interests include the philosophy of science and fad disorders. He has contributed to the American journal Scientific Review of Alternative Medicine.

Selected Books (in Dutch):

  • Manuscript Found Besides an Obstetric Forceps (in Dutch; 2011)
  • Wrong Tracks in Medicine (dissertation, 2004)
  • It Cannot Be Called Healing: Biographical Sketches of the Twenty Most Notorious Practitioners of the 20th Century (2001)
  • Quacks in Potassium Hydroxide (2000)
  • Contemporary Quackery (1992)

Selected Publications:

  • “Please, let not Western quackery replace traditional medicine in Africa” (with TPC Dorlo), Tropical Medicine and International Health, 2012 Dec 10;. [DOI]
  • “The use of complementary and alternative medicine in Dutch fertility patient” (with IMM Doodeman), Human Reproduction, 2010; 25(supp):i20-i21. [abstract]
  • “Alternative medicine in infertility: patients feeling in control?”, Human Reproduction, 2010; 25(supp):i98-i99. [abstract]
  • “[Dutch parliament legitimizes harmful quackery]” [in Dutch] (with FS van Dam), Nederlands Tijdschrift voor Geneeskunde, 2010; 154:A1814. [abstract in English]
  • “In the interest of all who value their purse and their health: a brief history of the ‘Vereniging tegen de Kwakzalverij’—Society Against Quackery—of the Netherlands,” Evaluation & The Health Professions, 2009 Dec; 32(4):431-450. [abstract]


  • Knight of the Order of Orange-Nassau, 2006, for outstanding service to society in his opposition to quackery.
  • Hector Treub Prize, 2002, for important social achievement in health care, particularly in the field of obstetrics and gynecology.

In the News:

  • Dutch sceptics have ‘bogus’ libel decision overturned on human rights grounds,” by Le Canard Noir, The Quackometer [online only], 2009 Aug 3. “...The Dutch sceptics group, Vereniging tegen de Kwakzalverij (VtdK – The Society against Quackery) have managed to overturn a important court ruling that was preventing them calling quacks quacks. In a remarkable case, that in many ways closely parallels the BCA vs. Simon Singh case in the UK, a judge has decided that using a narrow definition of the word ‘quack’ that a previous ruling was forcing the group to defend in a libel case, was incompatible with Article 10 of the European Convention of Human Rights. … In publishing their top 20 list, the Society were quite careful to explicitly define what they meant by the word ‘quack’. They said, (Google translation) ‘Quackery is:
    (a) any professional act and/or the extending of advice or assistance related to the state of health of either man or animal;
    (b) which is not founded on contemporary and/or empirically tenable hypotheses and theories;
    (c) which is actively propagated among the public (“over-promotion”);
    (d) which has not been tested on efficacy and safety within the professional group;
    (e) which is (usually) performed without consultation of fellow practitioners.’’”

The Online Cees Renckens:

VtdK in Dutch VtdK in English [via Google translation]

Wikipedia logo (Renckens, English translation from Dutch)

Wikipedia logo (VtdK)