216 Aristotle and his school
the animal kingdom, in particular for his philosophical anthropology, and
to what extent the description of these bodily structures and processes is
guided by teleological concerns. However, such a study would have to take
into account the different levels of explanation on which Aristotle is at work
in various contexts as well as thetypesof context in which Aristotle expresses
himself on these issues. The following typology of contexts (which does
not claim to be exhaustive) would seem helpful:
( 1 ) First, there are contexts in which Aristotle explains the bodily struc-
tures with a view to their suitabilityK
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!#Lfor the
fulfilment of the psychic functions in which they are involved, for exam-
ple, when he describes the structure of the human hand by reference to the
purpose it is intended to serve,^35 or man’s upright position with a view to
man’s rational nature.^36 This is because he believes that a purely material
description of the bodily structures would be just as insufficient as a purely
formal description of soul functions, because it ignores the suitability of
these structures for the exercise of the powers for the sake of which they
exist and with a view to which they are shaped. As G. E. R. Lloyd sum-
marises: ‘whenever he is dealing with an instrumental part that is directly
concerned with one of the major faculties of the soul identified in theDe
anima, Aristotle cannot fail to bear in mind precisely thatthatis the func-
tion that the part serves, and he will indeed see the activities in question as
the final causes of the parts’.^37 However, as Lloyd himself recognises, this
is just one of several concerns Aristotle has in the zoological works, and it
is not consistently implemented.
( 2 ) Secondly, there are contexts in which the ‘mechanics’ of psychic
processes are discussed in physiological terms. Thus in his explanations
of memory, recollection, sleeping and dreaming, Aristotle goes into great
(though not always clear) physiological detail to describe the bodily parts
involved in these ‘psychic’ activities and the physical processes that accom-
pany them (e.g. the discussion of the ‘bodily imprints’ in memory,^38 or of
the ‘reactivation’ of sense-movements in sleep due to the withdrawal of the
blood).^39 As I have tried to show elsewhere, these discussions deal with op-
erations of the sensitive (and perhaps also the intellectual) part of the soul
under rather special circumstances, but they also have important implica-
tions for the physiology ofnormalsense-perception (on which the relevant
sections inOn the SoulandOn Sense Perceptionare rather uninformative).^40
(^35) Part. an. 687 b 6 ff. (^36) Part. an. 686 a 27 ff. (see below); cf. alsoIA 706 a 19.
(^37) Lloyd ( 1992 ) 149. (^38) Mem. 450 a 27 ff. (^39) Insomn. 459 b 7 ff.; 461 b 11 ff.
(^40) See van der Eijk ( 1994 ) 75 – 87.