In the language of the Stoa, "Nature" was a word of many meanings. There
was the "Nature" of the cosmos, and the "Nature" of man. In the latter,
the animal "nature," which man shares with a moiety of the living part
of the cosmos, was distinguished from a higher "nature." Even in
this higher nature there were grades of rank. The logical faculty is an
instrument which may be turned to account for any purpose. The passions
and the emotions are so closely tied to tne lower nature that they may
be considered to be pathological, rather than normal, phenomena. The one
supreme, hegemonic, faculty, which constitutes the essential "nature"
of man, is most nearly represented by that which, in the language of a
later philosophy, has been called the pure reason. It is this "nature"
which holds up the ideal of the supreme good and demands absolute
submission of the will to its behests. It is this which commands all men
to love one another, to return good for evil, to regard one another as
fellow-citizens of one great state. Indeed, seeing that the progress
towards perfection of a civilised state, or polity, depends on the
obedience of its members to these commands, the Stoics sometimes termed
the pure reason the "political" nature. Unfortunately, the sense of the
adjective has undergone so much modification that the application of it
to that which commands the sacrifice of self to the common good would
now sound almost grotesque.