The Sortis believe that you are bound by your fate.
In their cities they are grouped by generation and they are to refer to each other as Brother or Sister, they are to refer to the older generation as Father and Mother and the younger generation as Son and Daughter. This is to show that raising children is a community effort and that everyone in the city is not just your neighbour, but your family.
From a young ages each child is put through various tests to ascertain their aptitudes, and then they are trained for an occupation that it is determined to be best suited for them. Focusing on your occupation and improving your skill with it is the most important thing towards fulfilling your destiny. Anyone dabbling in something that is considered to be outside of your purpose is frowned upon if not openly punished, depending on how strict the city is.
A Sortis Magus is someone who has been found to have the greatest aptitude for controlling the power of the deistones, they are leaders who fight for their city and their power.