"The world is formed by a plethora of building blocks, called 'Elements.' The science of working with those Elements to change the world according to our will is called magic. Therefore, what magic can do is limited to what those elements can do. Anything else is in the realm of fairy tales."
That is the official narrative about magic that the Royal Academy drills into every single student. Actually, it's the narrative repeated by all magic schools throughout the human realms.
To do magic is to work with the foundational elements of the world to change it according to your will.
You can create and manipulate fire, water, electricity, and other elements, but never destroy them directly. The only way to counter a spell is to oppose its effect using other elements.
Like using an earth shield to protect you from the explosion of a fireball.
Time magic? Space magic? Nope.
Creating poison with magic? Nope.
Healing? Nope, as well.
