happening and more than one account of their nature which harmonizes with perception'. Epicurus'
scepticism is amateur, and the truth is that he does not care to know. 'If we recognize that an event can
happen for a variety of reasons, we shall be as tranquil as if we knew that it happened in precisely this
way.' At bottom one thing matters: 'only let superstition be absent'.
The Stoics, like the Epicureans, were cavalier about particular scientific theories but intensely concerned
with the foundations of physics. 'They hold that the first principles of things are two in number: what acts,
and what is acted upon. What is acted upon is qualityless substance, which is matter; what acts is reason
in matter, which is god.' Since 'Zeno thought that nothing could in any way be caused by anything
incorporeal', the active principle is itself material, and the Stoic universe is as thoroughly corporeal as the
Epicurean. But the Stoics admit no empty space into the world, and do not suppose that matter comes in
atomic parcels. Rather, the world is a continuous mass of stuff, gapless and infinitely divisible; it is a
blend of the two principles, 'the mixtures of which' according to Chrysippus, 'are through and through ...
and do not occur by way of circum-location or juxtaposition'.
The active principle, sometimes characterized as fire or 'breath', fashions the world, first creating the four
elements of fire, air, water, and earth, and thence forming the structures of the cosmos. The universe 'is
governed by reason and providence', for the active principle 'is an immortal living thing, rational, perfect
in felicity, admitting no evil, providing for the world and the things in the world' - and it is called Zeus
and Hera and Athena and the like. The world is not a machine, unthinking and purposeless: it is imbued
with intelligence, and any explanation of its functionings must be primarily teleological.
We are little parts of the cosmic animal, having a proper place in its natural economy. Like Epicurean
souls, Stoic souls are corporeal. They are fragments of the active principle, and a later writer explains that
the soul 'is not contained in the body as in a vessel - like liquid in a cask - but is wonderfully blended and
mixed throughout the whole of it, so that not even the smallest part of the mixture fails to have a share of
each constituent'. Chrysippus agrees with Epicurus that the soul does not survive the dissolution of the
body, but he can offer us a sort of spasmodic immortality: 'after our deaths, at a certain period of time we
shall again come to be in the state in which we now are'. For the cosmos enjoys a cyclical history. At
fixed intervals, the world is consumed by fire: after the conflagration, a new world, just like its
predecessor, is formed, itself doomed to fiery destruction. Each world contains us: we shall live again,
infinitely often - and we have already enjoyed infinitely many lives, each identical in its biography.
But man's place in the world is in one respect problematical, both for Chrysippus and for Epicurus. For
men can act freely, and free action is not easily contained in a rule-governed universe.
Epicurus' world, though mechanistic, was not determined by iron necessity. The atoms sometimes deviate
from their normal trajectories by a minute amount: and the deviation, or swerve, has no cause. 'If the
atoms do not swerve and thereby produce a sort of beginning of motion which breaks the bonds of fate so
that cause does not follow cause everlastingly, what is the source of the free will which living things
possess throughout the world?' Freedom implies the absence of external necessitation, and the postulated
swerves ensure that necessity is not ubiquitous. Free actions are determined by the agent's will. And the
will, thanks to an uncaused deviation in the atoms of the soul, is not wholly dependent on external events.