The dual view is based on the principles "as above, so below" and "as below, so above".
In this view it is implied that there is a sort algorithm for awareness: there are higher, bigger and macro states of consciousness, and there are also lower, smaller and micro states of consciousness.
We may or may not move through these different levels fluidly, but in approaching a new situation we can make use of our existing knowledge, experience and views.
The dual view is simply the 'rule of thumb' of psychic views: it is better to approach the situation/problem with confidence of familiarity and not the fear/unconfidence of the unknown.
"As below, so above."
Does the dual view work? Yes of course, and of course not.
It works because the universe is holistic and moves/spirals/changes through all of its aspects; thus, it is reasonably sure to assume that what we don't know has something to do with what we do know.
It doesn't work because if we cross the threshold of simplicity into the domain of simplisticness, we have sacrificed valuable accuracy. If we sacrifice too much accuracy, the insights and information we gain from the dual view moves from 'useful' to 'useless' to 'counter-useful'.
It's good to have a rule of thumb. Keep it handy.
Employ the dual view with flexibility, and as new insights/currents come, be ready to make major changes or outright cast the whole view away.