In the philosophy of the I Ching, there is a basic truth that in every moment, we have a choice between manifesting the Superior Individual or the inferior person.
Among those who practice cultivation, however, there may be some question as to just what the "Superior Individual" is. In the course of cultivation, one might get a sense of the Superior Individual being some outside entity, the "higher self" sending them messages or guiding their life.
So some have developed a conception where the Superior Individual is some kind of outside spiritual, angelic or divine entity.
But in fact, the Superior Individual is basic part of ourselves. It is not a separate being at all, it is us. The best of us.
This sense of differentness, of the Superior Individual seeming like another being with its own intelligence and communicating with us is a product of people's primary identification with the 'inferior person', which is also a part of us. Thus, we have become separate from the 'higher self'.
Why are we separated from our higher self?
We aren't, but it seems this way.
The issue is this: we are a species in the process of evolution. Our consciousness has multiple layers, which can be generally divided into two parts. In the context of I Ching studies (including the Yi Fa work) these are described as "World" and "Heaven". To Nietzche it was "last man" and "super-man". In others, it could be called "animal" and "divine".
The Chinese actually say that there are two parts to the human soul: Po and Hung. The Po is the part of us that is animal instinct plus conditioned behavior. The Hung is the part of us that is our fullest potential and true Individuality (as opposed to the 'persona' of our inferior po-soul).
We can, at every moment, choose to associate with one or the other. But on account of our intermediary condition and because of our social conditioning we tend to more directly identify ourselves as the "Inferior Person". So much so, that the Superior Individual can sometimes feel like it's a separate entity, some kind of guiding spirit.
You will find, if you engage with discipline in a sincere long-term course of spiritual cultivation, that over time, you will become more and more identified as one with the Superior Individual. At that point, the 'ideas' of the Superior Individual will be identical to your own, and the notions of the inferior person, which will still be present, will instead be the ones that appear to be foreign.