The Secret Doctrine
The Secret Doctrine - H.P. Blavatsky - 1888
The Secret Doctrine builds on 3 fundamental propositions:
The 1st proposition is that there is one underlying, unconditioned, indivisible Truth, variously called "the Absolute", "the Unknown Root", "the One Reality", etc.
The 2nd proposition is "the absolute universality of that law of periodicity, of flux and reflux, ebb and flow".
The 3d proposition is: "The fundamental identity of all Souls with the Universal Over-Soul... and the obligatory pilgrimage for every Soul—a spark of the former—through the Cycle of Incarnation (or 'Necessity') in accordance with Cyclic and Karmic law, during the whole term."