Anthroposophic medicine (or anthroposophical medicine) is a form of alternative medicine based on pseudoscientific and occult notions. Devised in the 1920s by Rudolf Steiner (1861–1925) in conjunction with Ita Wegman (1876–1943), anthroposophical medicine draws on Steiner's spiritual philosophy, which he called anthroposophy. Practitioners employ a variety of treatment techniques based upon anthroposophic precepts, including massage, exercise, counselling, and substances. Many drug preparations used in anthroposophic medicine are ultra-diluted substances, similar to those used in homeopathy. Homeopathic remedies are not medically effective and are generally considered harmless, except when used as a substitute for a scientifically proven and effective prevention and cure. In certain European countries, people with cancer are sometimes prescribed remedies made from specially harvested mistletoe, although no evidence of clinical benefit exists. Some anthroposophic doctors oppose childhood vaccination, and this has led to preventable outbreaks of disease. Anthroposophic medicine departs from fundamental biological, physical and chemical principles in several respects. For example, Steiner said that the heart is not a pump, but that the blood in a sense pumps itself. Anthroposophic medicine also proposes that patients' past lives may influence their illness and that the course of an illness is subject to karmic destiny. Professor of complementary medicine Edzard Ernst and other physicians and scientists including Simon Singh and David Gorski have characterized anthroposophic medicine as pseudoscientific quackery, with no basis in reason or logic. The first steps towards an anthroposophic approach to medicine were made before 1920, when homeopathic physicians and pharmacists began working with Rudolf Steiner, who recommended new medicinal substances as well as specific methods for preparation along with an anthroposophic concept of man. In 1921, Ita Wegman opened the first anthroposophic medical clinic, now known as the Klinik Arlesheim, in Arlesheim, Switzerland.