The repair allotted as the task of each individual soul... The Supreme Mind did not create more souls than were necessary for the task, for He calculated everything – the human form as the key to the way man’s service and the commandments of the Torah are ordered, and the human form as the key to the way the souls are ordered. Thus each soul has its own root repair to carry out, and this contributes to the successive repair of all aspects of existence according to what is allotted to that soul.
...stems from the way this interconnection of MaH and BaN is arranged... For the souls are rooted in these levels that we have been discussing (“the Yechidah is from Adam Kadmon” – Shaarey Kedushah 3:2), and it is from there that they receive their mission, each according to its particular root. If this is the level where the souls are rooted, it is because the entire governmental order operates first and foremost through and for the souls, and from them it extends to all the different creations and all the worlds. (The entire creation serves man, and therefore the creation is arranged according to the service required of the souls.)