Although intra- and interpersonal influences have long been acknowledged in medical science to affect an individual's health both positively and negatively, the impact of non-local, transpersonal influences are generally denied in contemporary medical science.

The present paper examines anecdotal, ethnographic, anthropological, clinical, and experimental evidence suggesting that non-local, transpersonal influences may exist, and that these may exert a negative and even fatal impact on human health. The possible relationship of these negative influences to scientific findings in other anomalous areas, such as the studies in human/machine interaction at the Princeton Engineering Anomalies Research (PEAR) Laboratory, are discussed. The author concludes that the evidence favoring the existence of non-local, negative, transpersonal influences is considerable, and that the implications for medical research and clinical practice are profound.