Whereas God created three sorts of living natures, to wit, angelical, rational, and brutal, giving to angels an intellectual and to beasts a sensual nature, he vouchsafed unto Man both the intellectual of angels, the sensitive of beasts, and the proper rational belonging unto man; and because in the little frame of man's body there is a representation of the universal. . . therefore was man called microcosmos, or Little World.

—A Treatise of Melancholie, Timothy Bright.

There was, (and it still is for some people), a pervasive cosmic world view where the relationship between all existence is defined within a strict structured hierarchy known as scala naturae or the Chain of Being. Originating with the Neoplatonists, but finding its niche in the Christian Era, its’ premise (plentitude) states that the universe is ultimately perfect and all existence is possible without contradiction. Using the chain analogy, this means every link has its’ place. There are no empty links. No link represents more than one object and the continuity of the links is maintained in that each differs by the least possible degree with the next one.

In this fixed model of the universe, object’s are graded and placed in this hierarchical structure according to their relative portions of spirit to matter.[1] The greater amount of spirit contained, the higher the placement and closer to ens perfectissimum (-God). Each group type was then further divided and graded accordingly. This gradation extended into all avenues of reality and not just the physical but the metaphysical and spiritual planes as well.

Universal interdependence
Within this universal order is a labyrinth of interconnecting sympathetic relationships called correspondences. Because each link reflects a microcosmic view of the whole, it shares a commonality among the other planes of existence. Therefore, associations can be made between the macrocosms and microcosms existing throughout structure.

These correspondences are indicative of one of the fundamental principles that governs magic, alchemy and metaphysical philosophy. "That which is above is as that which is below, and that which is below is as that which is above."[2] This is now abridged in the popular phrase "as above, so below".

"To grasp the invisible elements; to attract them by their material correspondences; to control, purify and transform them by the living power of the spirit; this is Alchemy."

—Paragranum.

A New World View
Change and flexibility are not components of the Great Chain of Being but they were what ultimately lead to its' demise. By the end of the Renaissance, concepts like individualism, humanism, and renewed interest in science and nature allowed for new ideas and evolutionary thoughts. Reformations were occurring both in society and within the church causing disorder within this universal orderliness. The final blow came in the late 18th and early 19th century when scientific evidence began to indicate that species do change and evolve and some even become extinct. By the end of the 19th century many rejected the rigidity of the Great Chain of Being in favor of Charles Darwin's Natural Selection.[3]

Notes:
1.The basis for this determination is apparant intellect and perfection.
2. Smaragdine Tablet of Hermes translated by Dr. John Everard.
3. There is still friction between creationism and evolution adherets.
4. It is the general consensus amoung the Pagan community that humans are part of nature and not outside it or even above it.

Alchemy: Ancient and Modern —Herbert Stanley Redgrove
The Magician's Companion —Bill Whitcom
The Great Chain of Being
Peter Suber - The Great Chain of Being
The Three Estates