This volume represents the high-water mark of the thought of Eliphas Levi. It may be regarded as written by him as his Thesis for the Grade of Exempt Adept, just as his "Ritual and Dogma" was his Thesis for the grade of a Major Adept. He is, in fact, no longer talking of things as if their sense was fixed and universal. He is beginning to see something of the contradiction inherent in the nature of things, or at any rate, he constantly illustrates the fact that the planes are to be kept separate for practical purposes, although in the final analysis they turn out to be one. This, and the extraordinarily subtle and delicate irony of which Eliphas Levi is one of the greatest masters that has ever lived, have baffled the pedantry and stupidity of such commentators as Waite.