Helena P. Blavatsky's Isis Unveiled (1877)

The occultists who were responsible for the popularization of the paraphrase generally understood it in the context of Emanuel Swedenborg's (1688–1772) doctrine of the correspondence between different planes of existence, a strongly elaborated version of the classical macrocosm–microcosm analogy. This interpretation was pioneered by Helena P. Blavatsky (1831–1891),^[12] whose works contain some of the earliest occurrences of the phrase as an independent axiom. Generally writing from a perennialist perspective, Blavatsky associated the phrase with a number of historically unrelated thought systems such as Pythagoreanism, Kabbalah and Buddhism.^[13]

From Blavatsky's Isis Unveiled (1877):

His [sc. Swedenborg's] doctrine of correspondence, or Hermetic symbolism, is that of Pythagoras and of the kabalists—"as above, so below." It is also that of the Buddhist philosophers, who, in their still more abstract metaphysics, inverting the usual mode of definition given by our erudite scholars, call the invisible types the only reality, and everything else the effects of the causes, or visible prototypes—illusions.^[14]

There is no prominent character in all the annals of sacred or profane history whose prototype we cannot find in the half-fictitious and half-real traditions of bygone religions and mythologies. As the star, glimmering at an immeasurable distance above our heads, in the boundless immensity of the sky, reflects itself in the smooth waters of a lake, so does the imagery of men of the antediluvian ages reflect itself in the periods we can embrace in an historical retrospect. "As above, so it is below. That which has been, will return again. As in heaven, so on earth."^[15]

The spirit of a mineral, plant, or animal, may begin to form here, and reach its final development millions of ages hereafter, on other planets, known or unknown, visible or invisible to astronomers. For, who is able to controvert the theory previously suggested, that the earth itself will, like the living creatures to which it has given birth, ultimately, and after passing through its own stage of death and dissolution, become an etherealized astral planet ? "As above, so below;" harmony is the great law of nature.^[16]

The Kybalion (1908)

Though retaining the interpretation of the phrase in terms of Swedenborg's doctrine of correspondence, it was somewhat more closely associated with the philosophical mentalism (the primacy of mind as the active cause of things) of the ancient Greek Hermetica by the anonymous author of the Kybalion (1908, 'Three Initiates', perhaps William W. Atkinson, 1862–1932).^[17] What follows are some literal quotes from the book:

II. The Principle of Correspondence.

"As above, so below; as below, so above"– The Kybalion.

This Principle embodies the truth that there is always a Correspondence between the laws and phenomena of the various planes of Being and Life. The old Hermetic axiom ran in these words: "As above, so below; as below, so above." [...] This Principle is of universal application and manifestation, on the various planes of the material, mental, and spiritual universe– it is an Universal Law. [...] Just as a knowledge of the Principles of Geometry enables man to measure distant suns and their movements, while seated in his observatory, so a knowledge of the Principle of Correspondence enables Man to reason intelligently from the Known to the Unknown. [...]^[18]

The Planes of Correspondence.

"As above, so below; as below, so above."—The Kybalion.

The great Second Hermetic Principle embodies the truth that there is a harmony, agreement, and correspondence between the several planes of Manifestation, Life and Being. This truth is a truth because all that is included in the Universe emanates from the same source, and the same laws, principles, and characteristics apply to each unit, or combination of units of activity, as each manifests its own phenomena upon its own plane. [...]^[19]

[...] The old Hermetic axiom, "As above so below," may be pressed into service at this point. Let us endeavor to get a glimpse of the workings on higher planes by examining those on our own. The Principle of Correspondence must apply to this as well as to other problems. Let us see! On his own plane of being, how does Man create? Well, first, he may create by making something out of outside materials. But this will not do, for there are no materials outside of THE ALL with which it may create. Well, then, secondly, Man pro-creates or reproduces his kind by the process of begetting, which is self-multiplication accomplished by transferring a portion of his substance to his offspring. But this will not do, because THE ALL cannot transfer or subtract a portion of itself, nor can it reproduce or multiply itself— in the first place there would be a taking away, and in the second case a multiplication or addition to THE ALL, both thoughts being an absurdity. Is there no third way in which MAN creates? Yes, there is—he CREATES MENTALLY! And in so doing he uses no outside materials, nor does he reproduce himself, and yet his Spirit pervades the Mental Creation. Following the Principle of Correspondence, we are justified in considering that THE ALL creates the Universe MENTALLY, in a manner akin to the process whereby Man creates Mental Images. [...]^[20]

[...] The student will, of course, realize that the illustrations given above are necessarily imperfect and inadequate, for they represent the creation of mental images in finite minds, while the Universe is a creation of Infinite Mind—and the difference between the two poles separates them. And yet it is merely a matter of degree—the same Principle is in operation—the Principle of Correspondence manifests in each—"As above, so Below; as Below, so above." And, in the degree that Man realizes the existence of the Indwelling Spirit immanent within his being, so will he rise in the spiritual scale of life. This is what spiritual development means—the recognition, realization, and manifestation of the Spirit within us. Try to remember this last definition—that of spiritual development. It contains the Truth of True Religion.^[21]