What's up with this.. This is a mixed bag but most of the games have this in common. Not entirely sure what to do.
II has 'learning' attached to every battle command/stat and spell;
III and V have learning inherited through jobs for abilities which in turn unlock or allow use of commands, spells, et al.
VI allows you to equip a special type of item (or any item) which lets the user learn magic at a given rate. (In fact current progress is even viewable in the spell list screen.)
So, we need a system capable of implementing the aforementioned, but one that does not need to stick it's nose nose into every part of the code that it can be used by, and not so generic that it would be less error-prone to script something from scratch rather than use as a core feature.