Arcane casters are given free range when learning about the universe and in the development of new spells. This is intended to further the galaxy as a whole, and is the main objective of the Galactic Accord. But like all things there are those who will abuse such a privilege.
There are rules for how the universe works. By knowing those rules you can change reality, and that’s what magic is. The same methods for making fire or water appear from thin air can also create life from nothing. The Summoner creates living creatures from a dimension known as the Outer Plane, one of the realities that overlaps our own. The Outer Plane is a playground where thoughts are given shape and form. Not all summoners abuse this knowledge to create monsters, but summoning is still something of a taboo subject.