from the Liber Juratus:Sloane 313 :

"Elemental Demons are neither good nor evil, neither benevolent nor malevolent by nature; thus they may be employed for either good or evil purposes. It is not the demons, nor the calling of them, nor magical art that is evil, rather it is the use that evil men may make of magical art that is evil. There is no harm in magical art that is not first in the hearts of evil men; those who are good, and intend good, produce good: those who are evil, and intend evil, produce evil. Men who are good and faithful need fear no harm from magical art, for demons are conquerable and made subservient to the will of a good man by fortitude and courage".