Thaumaturgy (from the Greek words thaûma, stem thaumat-, meaning “miracle” or “marvel” and érgon, meaning “work”) is the capability of a saint or magician to work miracles. It is sometimes translated into English as wonderworking. A practitioner of thaumaturgy is a thaumaturge. In the 16th century, the word thaumaturgy entered the English language meaning miraculous or magical powers. Thus thaumaturgy means making and operating physical devices, based on early engineering principles, to produce an effect. However, some who used the title thaumaturge related thaumaturgy to theurgy, a Greek term for a branch of magic concerned with spiritual matters. In this view, the material effect produced by a thaumaturgical device was considered to actually be caused by a spiritual ritual (theurgy), which influences the material sphere by way of the more subtle, ethereal realm.