Ah. My mistake then. I thought magnus in itself is a field of study.  However it is now clear that the schools of magnus themselves are the field and magnus is not a science but rather science in itself. That is there is no direct study of magnus as by the analogy they are different fields where each specialist can fund their niche.

I'll go with something far more simple then as it seems I am confused by the mechanisms to create something complicated as a psionic illusionist.