Photomancy is, nominally, the manipulation of light. This is indeed within a photomancer's purview, but the school is most well-known for its healing capabilities. This might make little sense until one understands that the spirits of people are actually light spirits. These spirits function to record the person they are generated by. The photomancer can pull on these records to restore an earlier bodily state, usually localized, such as healing a laceration. This can work on the brain as well, allowing a photomancer to induce someone to forget things. However, at current understanding of the brain, it must be the entire brain that is affected, so it is in effect a total replacement of the current brain by an earlier state, which can lead to much confusion, as the patient who wanted to forget something has no idea why they're there - and if the thing they wanted to forget is long enough ago, this confusion can be quite extreme. This, of course, has much more nefarious uses than alleviating painful memories. However, in all cases, there is a certain time limit, as the light spirit has finite informational space available. If the injury happened too long ago, the desired previous state cannot be restored. In addition, photomancers cannot resurrect people on their own, as the spirit leaves the body upon death. Resurrection is possible, however, in cooperation with a necromancer, who can manipulate the spirit in question. But then, only if the person is willing - unless the necromancer is just that powerful - as the spirit of an unwilling person can, of course, resist.