As you can tell from Tauren's post, you basically need nature magic to heal afflictions. The sole exception really is if you play T'ien C'hi, since one of their heroes has the healing ability.
Personally - I think it sucks that you have to have decent nature magic on your pretender to get healing, depending on your nation. Or you can hope to get lucky on a province (jade amazons) or magic site, which you'll probably need anyway, once your pretender with the nature magic gets feebleminded or mute.
