Reference: Course on Subject Clearing
(1) Unknowable simply means that you do not know everything in advance. You have certain observations, and among those observations there are many gaps of what you do not know.
(2) You postulate to fill these gaps. This may narrow the gap but some smaller gaps still remain. As you continue to postulate, you develop a system of postulates to explain what you do not know.
(3) Such a system of postulates must be consistent in itself to be able to predict consistently what you do not know. Everything that you know is based on this system of postulates.
(4) When you come across something that your system of postulates could not predict then you have an inconsistency in your system. You then have to recalibrate your system of postulates to be able to account for this new observation.
(5) Something unknowable still remains and it pulls you forward in developing your system of postulates. This continues on an individual basis life after life. It comes to be shared by others and starts to develop on a social basis.
(6) Ultimately, it has to become a universal system of postulates as inconsistencies continue to be resolved.
(7) The unknowable still remains as that which is yet to be explained fully by the universal system of postulates.
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