Body and Soul in Ancient Philosophy

Aristotle on desire and action 303
quired to make the coat she aims to produce. Her actions are vivid examples
of inextricably psycho-physical processes.
Consider the movements of pneuma involved in reproduction: if
they are like those involved in weaving, one will not be able to define
them without reference to the goals and capacities of the agent. In the
case of the generating parent, the movements in the pneuma will follow
from his nature, not from conscious reasoning (744a33 –6, see 740b27–
36). But in both this case and that of weaving the nature and identity of
the movements themselves will be determined by the capacities and
goals of the agent (see PA 640b1 – 3, GA 734b11 –18). As the weaver
moves her hands in certain ways and uses certain materials because
they are appropriate to her goal, so the generating parent functions in
certain ways and operates on certain materials because they are appropriate
to its goal. In both cases, the relevant processes will be partially defined
in terms of the goals to be achieved. 11
In the specific case of the pneuma involved in action, while the relevant
movements will involve increase or decrease in size, change of
shape etc., there will be no defining the type of increase etc. involved
without reference to the goals and know how (action-producing skills)
of the agent. These too will be essentially the types of expansion and
contraction involved in achieving his goals. Like weaving, they will
be inextricably psycho-physical processes. While, in MA, Aristotle
does not specify the types of movement of the connate pneuma which result
in actions, these will be the ones required if the agent is to fulfil his/
her goal. From his viewpoint, nothing further need be said about which
types of movement are involved. He has defined (as in the case of weaving)
to the general category in which they will fall. It is not his task to
spell out the details.
5. Desire, the connate pneuma and action: An overview of
Aristotle’s account
We are now in a position finally to understand Aristotle’s brief and initially
disappointing comment in de An. 433b13 ff.: “The instrument by
which desire moves the animal is a bodily one: this is why it must be
investigated among the functions common to body and soul …” Desire
11 I discuss these issues in more detail 1988, 26 – 29.