Body and Soul in Ancient Philosophy

304
David Charles
moves the body by means of the connate pneuma, itself an essentially and
inextricably psycho-physical phenomenon. The movements in the pneuma
are essentially psycho-physical, increases in size and shape of the type
required to move the limbs so as to act. Desire can move the connate
pneuma because it too is essentially and inextricably psycho-physical:
the type of heating or cooling which is directed towards to a goal of
a given type (one seen as good for the organism). 12 It is because desire
is essentially a process of this type that it can succeed in moving the body
by means of a psycho-physical instrument. 13
The simplicity of Aristotle’s account (as sketched in de An. and developed
in MA) is a direct result of his conceiving of the relevant processes
as inextricably psycho-physical. Given this conception, he did not
need to address the Cartesian puzzle of how desire (a purely psychological
phenomenon) can move the animal. For Aristotle’s desire is not the
type of purely psychological phenomenon the dualist (or spiritualist)
philosopher takes it to be. In his picture, it cannot be defined as the
process it is without reference to some physical phenomenon. Nor,
when one desires is there a purely psychological phenomenon realised
in (constituted by/supervenient on) a distinct particular process of a robustly
physical type. Indeed, there need be no particular robustly physical
processes of this type present when the person desires to act (contrary
to the materialist account of these phenomena.) Aristotle’s simple
account only appears mysterious when we see it through the distorting
lens of post-Cartesian assumptions.
12 Since it is of the essence of the relevant process of heating that it is psychophysical,
its nature will be (in principle) distinct from any type of process
which is not essentially psycho-physical in this way. One cannot expect to
be able to define this type of process in terms of ordinary heating or cooling
since this type of heating is one which essentially serves certain goals. One
could label this as ‘vital heat’, understood as the type of heat which essentially
serves certain teleological goals in the organism.
13 The motivation for treating desire as essentially psycho-physical differs (somewhat)
from that given in the discussion of anger. No state is mentioned which is
inseparable from desire without reference to the body (as there is in the case of
anger). However, similar patterns of argument could be deployed: (i) desire has
to be a type of heating if it is to have the consequences it does (move the connate
pneuma) (ii) people are prone to desire objects when (and only when) they are in
given physical conditions. These arguments do not depend on finding a state
inseparable from desire without reference to the body (although there could,
of course be one: e.g. thinking one desires something).