Standings of Black Mage, Red Mage, and Summoner

[Kabooa]

Stuff

Except this is FF14, and the game clearly has a baseline for Thaumaturges being capable of healing magic. The reason it was removed wasn't a lore standpoint, but a class balance one, because having a high DPS class capable of party healing didn't work.

By your logic, Summoners shouldn't have access to a Raise type spell, but they do.

[Galvuu]

snip

According to the lore, actually, Black Magic precedes thaumaturgy.
The latter appeared due to the old Belah'dian/Sil'dihan issue with the zombies- someone had to take care of the dead (ritualistic magic on the corpses so they wouldn't go on a zombie rampage like the one that destroyed Sil'Dih).

Black Magic is Mhachi- you have Void Magic, siphoning power/aether from the Void to channel magical implements/destructive spells, and Shantotto's version of it (that we use), which uses the aether surrounding us and our own aether combined (which is why lesser mages burned to death trying to channel Enochian fire) to fuel the ultimate destructive spells (she's always ranting about "arts of destruction").

I doubt any healing/raising abilities fit BLM thematically in the world of FF14.