One book by Faivre is available for download here:The Eternal Hermes

If find it interesting that correspondence is the first proposition.  Plato conceved the physical universe as a mere shadow to what is real.  In this the physical world is is merely an extension of the spitirtual world and a poor fascimile at that.  Yet the physical world corresponds to the spiritual, as above so below, etc...  This would make this proposition a starting point in any philosophical enquirery and a basis for a theosophical world view in general.  Quantum Physics tells us that everything, reduced to it lowest form, is pure energy.  If we concieve that consicuousness is also energy then we can deduce that we are all part of an overall Conscious Energy from which we draw our lives and energy and being and that we can learn more about this Energy by understanding corrspondance. 

IMO, an initial assumption that there are conceptual things (subjectively knowable objects) called variously "God", "Nature" and "Human Being(s)" and that these are somehow separate and identifiable, already establishes pre-conditions that will color one's view and cause an unnecessary problem to be "solved" by a pursuit for "gnosis."