The Great Chain of Being

Medieval Christians thought this system was decreed by God. The Chain begins with the Primum Mobile, the First Mover, the Divine Being, and moves downward through lesser states of perfection, from the spiritual to the physical.

This idea comes from Aristotle, as does the concept of the Primum Mobile. But both Plato and the Neoplatonics shared some of these ideas.

The universe will function in perfect harmony only if all beings maintain their place in the Great Chain. Each being on the chain owes a duty to those above it and a responsibility to those below it.

It was crucial, then, for every being to know its place in the Chain, and then fulfill its own function without attempting to climb up or slip down the Chain. So people who give in to gluttony, greed, envy, anger, lust, or sloth sink down the chain by giving in to the bestial part of their nature, allowing it to override the rational, divine, part of their nature. On the other hand, people who have an overweening sense of pride are attempting to move above their station on the Chain.

Those seven moral failings above are usually known as the "Seven Deadly SIns." There's a specific order to the first six, based on their severity (lust, gluttony, greed, sloth, anger, and envy). While these sins are not excusable,, they are, to varying degrees, understandable. But the worst sin of all is pride, because it is an attempt to presume a position held by superior spiritual beings (either angels or God).

The Hierarchy

God	Primum Mobile, The First Mover, Source of All Being, Immutable, Pure Spirit
Angels	Immutable, Pure Spirit	Seraphim Cherubim Thrones Dominions Virtues Powers Principalities Archangels Angels
Humans	Both Spirit and Matter, equally mixed. Mutable, Subject to decay and death	Kings Princes Nobles Clergy Freemen Serfs
Animals	More Matter than Spirit	lions elephants dogs wolves horses other primates birds fish other marine life
Plants	More Matter, even less Spirit	oak trees shrubs bushes grain crops herbs . . . fungus & moss
Earthly Material	Pure Matter	diamonds gems gold silver marble limestone . . . soil & sand

Of course, if you look at the list of those beings on the Chain, there is only one type of being who is endowed with free will. A giraffe cannot wake up and decide to act like a lion. Nor can a maple seed decide to grow into an oak tree. They are as they were made. The same holds true of those spiritual beings, the angels. They are as they were created to be. Only humans can decide to act like a greater or lesser being, and thus only humans can actually upset the entire Chain of Being.