"Remote healing" is a phenomenon known to natural healers and other adepts of the paranormal, although is has so far hardly been examined systematically. The cardiologist Randolph Byrd, a former professor at the University of California, wanted to correct this situation. He carried out a 10-month, computer-assisted study of the medical case histories of patients who were admitted to the San Francisco General Hospital during this time with heart diseases. Byrd formed a group of experimenters, which consisted not of known healers, but of ordinary people, whose only special characteristic was that they were churchgoers who regularly prayed in one of the surrounding parishes. The selected people were asked to pray regularly for a group of 192 patients; the control group consisted of a further 210 patients, for whom nobody prayed as part of this experiment. This experiment took place under strictly controlled conditions: the patients were selected at random, and the study was carried out using the double-blind principle, whereby neither the patients, doctors nor nurses knew which patient belonged to which group.