D. Papineau Thinking about Consciousness

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the Berlin physiological laboratory of Johannes M�ller in the early 1840s, along with
Emil Du Bois-Reymond (1818 96) and Ernst Br�cke (1819 92). Together these students
were committed to a reductionist programme in physiology, aiming to show that
phenomena like respiration, animal heat, and locomotion could all be understood to be
governed by the same laws as operate in the inorganic realm.
This physiological context undoubtedly played a fundamental role in Helmholtz's
articulation of a universal principle of the conservation of energy. Because of his
physiological concerns, Helmholtz was interested in a principle that would cover all
natural phenomena, including those in living systems, and not just such manifestly
physical phenomena as mechanical motion, heat, and electromagnetism. Thus he took the
crucial step of asserting that all forces conserve the sum of kinetic and potential energy;
superficially non-conservative forces like friction are simply macroscopic manifestations
of more fundamental forces which preserve energy at the micro-level. This then enabled
Helmholtz to view the equivalences established by experimentalists like Joule, not just as
striking local regularities, but as necessary consequences of a fundamental principle of
mechanics. All natural processes must respect the conservation of energy, including
processes in living systems.
It seems likely that it was Helmholtz's specific combination of physiological interests and
sophisticated physical understanding that precipitated his crucial synthesis of the different
strands of research feeding into the conservation of energy. His desire to bring living
systems under a unified science allowed him to see that if we assume that all fundamental
forces are conservative, then this guarantees that a certain quantity, the total energy, will
be preserved in all natural processes whatsoever, including the organic processes that
formed the focus of his interest.11
A.4.4 Vital Forces
Helmholtz was part of a tradition in experimental physiology which set itself in
opposition to the previous generation of German Naturphilosophen. During the
eighteenth century the Newtonian categories of irritability and sensibility had gone
through various transformations, and by the end of the century were widely referred to
under the heading of Lebenskraft, or vital force , though there was continued
disagreement on the precise nature of such forces. Meanwhile, within the tradition of
German idealism, the notion of vital force had broken loose from its original Newtonian
moorings, and became part of a florid metaphysics imbued with romanticism and
idealism.
According to the Naturphilosophen, organic matter was infused with a special power
which organized and directed it. Following Blumenbach and Kant, Schelling took up the
term Bildungstrieb ( formative drive ), because of the excessively mechanical
connotations he discerned in the traditional term Lebenskraft. Schelling and the other
Naturphilosophen viewed this formative drive as having a quasi-mental aspect, which
enabled it to mediate between the archetypical ideas or essences of different species
and the development of individual organisms towards that ideal form. (See Coleman
1971: ch. 3; Steigerwald 1998.)
The experimental tradition which included Helmholtz can be seen as a reaction to these
extravagant doctrines. However, it is striking that many of those associated with this
tradition, though not Helmholtz himself, continued to admit the possible existence of vital
forces, both before and after the emergence of the conservation of energy. This is less
puzzling than it might at first seem. These physiological thinkers did not think of vital
forces as the mystical intermediaries of the Naturphilosophen, imbued with all the
powers of creative mentality. Rather they were reverting to the tradition of eighteenth-
century physiology. They viewed vital forces simply as special Newtonian forces,
additional to gravitational forces, chemical forces and so on, which happen to arise
specifically in organic contexts. Justus von Leibig (1803 73), the leading physiological
chemist of the time, and M�ller, Helmholtz's own mentor, are clear examples of
experimental physiologists who were prepared to countenance vital forces in this sense.
(Cf. Coleman 1971: ch. 6; Elkana 1974: ch. 4.)
A.4.5 Does the Conservation of Energy Rule out Vital (and Mental) Forces?
The interesting question, from our point of view is how far this continuing commitment
to vital forces is consistent with the doctrine of the conservation of energy. There is
certainly some tension between the two doctrines. It is noteworthy that Helmholtz
himself, and his young colleagues from M�ller's laboratory, were committed to the view
that no forces operated inside living bodies that are not also found in simpler physical and
chemical contexts (Coleman 1971: 150 4). Even so, there is no outright inconsistency
between the conservation of energy and vital forces, and many late nineteenth-century
figures were quite explicit, not to say enthusiastic, about accepting both.
In order to get clearer about the room left for vital (or mental) forces by the conservation
of energy, recall how I earlier distinguished two ways in which early Newtonian theory
might allow room for such sui generis animate forces. First, such forces might operate [ Pobierz całość w formacie PDF ]

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