MAX KISTLER
the primary, secondary and tertiary structures of the molecule 3.At each
step, the xistence of the structure is explained by virtue of local laws
of interaction between the parts of the system. Finally, the interactions
of the parts of the molecule, in the positions they occupy within the
tertiary structure, lawfully bring about the quaternary, overall structure
of the molecule: this conformation gives the molecule the causal power
of transporting oxygen in our body.
The existence of new causal powers of this kind is not sufficient o
establish l~we's dualist thesis that these new powers are independent
of the powers of the parts of the system. Rather, the causal powers of
haemoglobin molecules eem to belong to the same category of "weakly
emergent" causal powers as "the causal powers of liquid water" (Lowe
1993, p. 636; 1996, p. 81): they are new in the sense that they only belong
to systems of a certain complex structure but not o any of their parts. H20
molecules do not possess any of the causal powers of liquid water, such
as transparency and a specific viscosity. Nevertheless, these powers are
only weakly emergent because they are "explicable in terms of the causal
powers and relations of its constituent molecules" (Lowe, ibid.).
Lowe fails to show that mental events are emergent in any stronger
sense than such macroscopic physical or rather chemical properties. I
do not thereby deny that it would already be a substantial result to show
that mental properties are "weakly emergent" in the sense indicated,
to the extent hat this is incompatible lx~th with eliminativism and the
type-identity of mental and neurophysiological properties.
Lowe's main argument for the thesis that some mental events are
strongly emergent is that it is empirically possible, and plausible, that
there are mental and neural processes, uch as the processes leading to
voluntary actions, in which "it is impossible to map token neural events,
or fusions thereof, onto token conscious events in a way which preserves
isomorphism between their respective causal iaisons" (Lowe 1993, p.
638/9; 1996, p. 84).
The empirical possibility Lowe has in mind has the following
structure: if we trace back in time the neural causes of three different
voluntary bodily movements B r B z, B~, which are executed at the same
time t, we shall find that these causes quickly spread out over large areas
320