Dowsing: The Instabilities of Evidential Competition

The instability of competition among competing theories is illustrated by the rivalry between proponents and critics of dowsing. Over four centuries, they competed at the level of theory, advancing different conceptions of the processes at issue, and at the level of phenomena, disputing whether the dowsing successes were pervasive or illusory. Mutually reinforcing evidential successes by critics eventually led to securing their position at the expense of that of the dowsers, whose views were reduced to a pseudoscience.