Common magic is set apart by its wide range of practitioners: priests and laity, educated and uneducated, men and women, specialists and occasional users. Gratian's chapter was important for shaping definitions of common magic because many later churchmen used it as the basis for their own writings. Much of information about common magic comes from the writings of clergy, especially for the Middle Ages. There are also sources for common magic written from a less hostile perspective: they recorded magical practices because they were useful or interesting. The common magic could be used actively to bring about a result, for example, to heal, predict the future or cause harm, and it could also be used defensively to ward off evil influences and protect people, animals and crops against the things that threatened them. One of the best-documented uses of common magic was for healing. Charms and amulets were widely used and recommended by educated people as well as uneducated ones.