Someone once asked...
Someone answered with kindness...
In order for the Monad (the One) to understand itself, it was necessary to split itself into separate aspects. A student who has themselves for a master, has a fool for a teacher, and in the absence of any other alternatives, this was the path taken.
Another soul answered...
Many inspired texts talk about this but this speaker is the most lucid that I have found: http://phoenixsourcedistributors.com/html/j032/