Body and Soul in Ancient Philosophy

458
Jonathan Barnes
The soul, Tertullian thinks he has shown, is made of corporeal stuff.
But there are all kinds of stuff, and the next question is to determine
what sort of corporeal matter souls are made from. We know, of course,
that the stuff is breath. But what sort of stuff is breath? On any account,
it is a peculiar sort of stuff. For example, although – like all bodies – it is
tangible, it cannot be seen. Or more precisely, it is invisible to eyes of
flesh. As to the eyes of the soul, they can see breath – so much is evident
from Scripture. And there is nothing untoward there; after all, consider
the sun: it is invisible to the eyes of bats, and gazed upon by the eyes of
young eagles. 19
Again, soul stuff has this unusual peculiarity: remove some of it
from a man and what is left is not lighter but heavier. (A corpse is a living
body minus a soul, and it’s a well known fact that we all put on
weight when we die.) You find that hard to believe? Well, it is not unparalleled;
“after all, says Soranus, will they deny that the sea is corporeal
because when a ship is out of the water it is hard to move and heavy?”
(8.3). The comparison is hardly exact; but for all I know there may be
stuffs whose removal from a mixture leaves the remainder heavier.
A soul is not itself a stuff: it is corporeal insofar as it is made of stuff.
The body and the soul are both corporeal, and they are corporeal after
the same guise: each is a corporeal substance – the soul and the body, as
Tertullian puts it, are “sister substances” (52.3). Souls might, of course,
be corporeal without being substances. An Epicurean soul is a collection
of corporeal atoms, but it is not a substance. A Stoic soul is a parcel of
spirit, and – whatever the Stoics themselves may have thought – it is no
more a substance than is the wine in a bottle or the blood in a pig.
The difference between stuff and substance is crucial: Christian souls
are substances and therefore capable of independent existence – of existence
independent of any body with which they might be linked. To
be sure, by nature every soul is linked to another corporeal substance
and is one part of a composite substance: its sister is its other half. Nonetheless,
Christian eschatology proves – or rather, presupposes – that
souls may subsist alone and are substances. Tertullian himself does not
underline the point – indeed, he does not explicitly distinguish between
the claim that souls are corporeal and the claim that souls are corporeal
substances. Still, underlined or not, the point is capital.
If souls are corporeal substances, what sort of corporeal substances
are they? First, Tertullian remarks that, like any other corporeal sub-
19 See 8.5, quoting Apc 6.9 (see below, p. 460).