Many Wiccans believe in magic, a manipulative force exercised through the practice of witchcraft or sorcery. Many Wiccans agree with the definition of magic offered by ceremonial magicians, such as Aleister Crowley, who declared that magic was "the science and art of causing change to occur in conformity with will", while another prominent ceremonial magician, MacGregor Mathers stated that it was "the science of the control of the secret forces of nature". Many Wiccans believe magic to be a law of nature, as yet misunderstood or disregarded by contemporary science, and as such they do not view it as being supernatural, but a part of what Leo Martello calls the "super powers that reside in the natural". Some Wiccans believe that magic is simply making full use of the five senses to achieve surprising results, whilst other Wiccans do not claim to know how magic works, merely believing that it does because they have observed it to be so. Some spell it "magick", a variation coined by the influential occultist Aleister Crowley, though this spelling is more commonly associated with Crowley's religion of Thelema than with Wicca.