The primary principle of medieval Jewish magic was an implicit reliance upon the Powers of Good, which were invoked by calling upon their names, the holy Names of God and [Their] angels. The simple dependence upon names for every variety of effect obviated resort to all other magical acts with which the non-Jewish tradition has familiarized us. The magician who could produce wonders by the mere utterance of a few words had no need of the devious “business” of his non-Jewish colleague. It was the absence of the satanic element and the use of these names, that is, the employment of God’s celestial servants, which stamped Jewish magic with a generally far from malevolent character, for the angels could not be expected to carry out evil commands and thus contravene the essential purpose for which their good Lord has created them. And it was this principle, too, which kept Jewish magic securely within the bounds of the religion, and prevented it from assuming the rôle of anti-religion, as its Christian counterpart did.

Joshua Trachtenberg, Jewish Magic and Superstition: A Study in Folk Religion; The Truth Behind the Legend: Jewish Magic