the self is a social construct, it's created from other people, genetics, parenting, language, memes, ideas, behavioural patterns from teachers, peers and we add on bits and pieces from popular culture.
we develop a theory of mind, this usually takes the form of one mind per person, however if a mind behaves in a wildly differing and contradictory way it can lead to eccentric and dysfunctional ideas about self and others.
gradually we learn to apply a theory of mind to ourselves, recognising various intentions within, we also learn to deceive and lie.
we are under constant pressure to conform to consistent behaviour patterns. parents manipulate children in subtle ways to exhibit approved behaviour then express surprise when they bully their peers or exhibit any sort of difference.
we are very suggestible as a social species, we also present a constant self to the world, out of character behaviour attracts disapproval.
nothing instills belief more than acting out the behaviour that goes with it.
we don't do what we believe, we believe what we do, quite soon we internalise the idea of singular self because culture demands we have one.
this is aligned with monotheistic cultures. every theology demands a psychology, pagan cultures attempt to include a wide range of selves and behaviours, with gods and goddesses for just about everything allowing them to make love or war or what ever they wanted.
they acted with less of a sense of internal conflict than we do today. so as playthings of the gods the pagans allowed themselves more outbursts of impulsion's than we do. it seems that the greek and roman thinkers paid only lip service to their official religions while owing their ideas of the muse to the daemon, aand the genius as quasi - independent sources of personal inspiration.
monotheism split all behaviours, good and evil. it brings with it an increased sense of personal agency defined by the 'free will' to choose between what god and society wants and what you as an individual with impulses suggest. in monotheism you cannot always find a god that agrees with you so the daemons that inspired the pagans became the demons that culture now expects , thus creating a culture of self loathing and guilt.
secular law now controls democracy in the same way that religious law did. you can believe what you want as long as you don't express beliefs that are critical.astrologer, politician, priest, scientist, prostitute, school teacher, business person, drug addict, artist, police officer, model, lawyer, magickian, solider, erotic novelist. whilst many could have one of these jobs and another as a sideline or hobby it is unlikely that they will have two, the social conventions of consistancy discourage or prevent possible combinations, for no logical reasons.