That's not what you learn out of the discipline.

Blanket statement that may or may not apply, depending on the game.

In Final Fantasy 1, you fight a bunch of vampires on the way to the Lich, the Earth Fiend. The vampires go down quickly with Fire and Harm. Surprise, surprise, so does Lich.

Oh, look, here's a stronger version of Lich in the Temple of Chaos. He has more HP, but we now have Nuke, the most powerful fire spell. Cast Nuke and Harm, Fast on your melee, and fight is actually faster than the first time.