The idea of a Chain of Being, or Scale of
Creatures,
is one of the guiding threads of interpretation of the
universe worked out in Western science and philoso-
phy. Like all ideas developed through a process of
elaboration
lasting centuries, it can be defined only by
retracing its historical
development in all its varied and
often contradictory complexity. It will
suffice to point
out here what is constant in its many changing formu-
lations. The Chain of Being is the
idea of the organic
constitution of the universe as a series of links or
gra-
dations ordered in a hierarchy of
creatures, from the
lowest and most insignificant to the highest, indeed
to
the ens perfectissimum which, uncreated,
is yet its
culmination and the end to which all creation tends.
This idea entails, as we shall see in the sequel, a
series of essential
component ideas in the history of
Western metaphysics—the
principles of gradation, of
plenitude or fullness, and continuity, along
with the
principle of sufficient reason—and also defines
man's
place in the cosmos with psychological and moral, and
sometimes
even political, implications of fundamental
importance for intellectual
history.