I'm much prefer Terry Pratchett's depiction of witches. Practical women, with a good sense to know that a little bit of "headology" goes quite far, and any real magic is too much of a bother to actually use. That convincing someone you've put a curse on them is far more effective than actually putting a curse on them.

Do you really want to summon seven generations of ancestors to fix someone's broken arm? Or do you want to put splint on it, wave your hand and mumble, so that the patient thinks that you've cast some spell of healing, and tell them to keep it in a sling for a few weeks?