6. The Stoic Idea of Matter. At least one prominent
theory of antiquity is related to the foregoing systems
in so complex a way as to deserve separate treatment.
The Stoic theory is particularly remarkable in assigning
to matter many properties which were in contrast to
those defined elsewhere. The theory was in a sense as
insistent as the contemporary Epicurean atomism on
grounding all quality and action in a material base,
but this was matter that could act pervasively and
simultaneously throughout an organically structured
universe; matter the structures of which were not so
much productive of, as concomitant with, its modes
of action; matter that acted of necessity indeed, but
in the realization of rational and moral ends. The
“physics” of the school, whose greatest cosmologist was
Chrysippus (ca. 280-206 B.C.), was inspired by that of
Heraclitus: all the other three elements were ultimately
reducible to fire, the breath of life or soul (pneuma),
and their respective qualities followed from the dimin-
ished degree of their activity. The development of this
protean theory of the pneuma into an elaborate and
long-surviving theory of “nutritional,” “vital,” and
“animal spirits” might incline one to think it scientifi-
cally unfortunate, but its modes of explanation have
some affinities with contemporary ones in terms of
“fields,” “waves,” and “energy.” Toulmin and Good-
field credit the Stoics with “recognizing” and “tack
ling” “questions in matter-theory which have come to
the fore again only in the twentieth century” (The
Architecture of Matter, p. 108).