l form a static hierarchy, a ranking of entities that extended from the "lowest" forms of life to "higher" living beings (such as the lion, king of beasts), through the various gradations of human beings from peasants to nobles to Popes, and thence on upward through the hierarchy of angels to God.
This concept, in and of itself, has nothing to do with evolution; indeed, it is anti-evolutionary, since every member of the chain is fixed in its own place. The Great Chain of Being was developed, indeed, at a time when the world was assumed to be essentially static; in Aristotelian physics, for example, the only physics known to the earlier Middle Ages, the natural tendence of all objects was to come to rest once they reached their natural place in the universe.
But the Newtonian revolution of the seventeenth century replaced the old static world with a new world view in which everything was naturally in motion. Moreover, in the course of the eighteenth century the notion of progress, of gradual but inexorable betterment, began to take hold in Western thought. It was only natural that the ideas of change and of progress should eventually be applied to the Great Chain of Being. The natural implication of a "dynamic" chain of being was a sort of tree of life, gradually sprouting upward from the primordial ooze, branching outward into all the varied species whose relative places in the tree the Linnaean taxonomists had determined, and finally culminating in that highest and noblest flower: rational, bewigged, eighteenth-century Man.
This picture of the history of life could be called evolutionary, and it is a picture so consistant with the world view of the late eighteenth and early nineteenth centuries that we should not be surprised to find various evolutionary ideas being offered from the late eighteenth century on. But the description above, though evolutionary, does not offer a theory of evolution--a mechanism throu...