Re: Sherrington
I fully agree with these sentiments. First, Sherrington was
unreliable as a historian. Second, he was obscure in his
philosophical musings.
As regards the first point (Sherrington's unreliability as a
historian): here is an example. In his book on Fernel (see
full reference below), Sherrington wrote:
the brain, despite its look of solidity, is a hollow organ; it has
in it four large chambers containing watery fluid. Tradition
regarded these as the reservoirs of the Galenical ``spirits'',
which were generated at the base of the brain. The movement of the
brain was taken to be the rhythmic charging of these reservoirs
with ``spirits''. The fourth chamber, the hindmost, communicates
with the three chambers in front by a narrow tunnel. The entrance
to this tunnel is overhung by a small stalked gland. Certain
anatomists taught that this gland acted as a valve controlling the
passing of spirits backwards and forwards through the tunnel.
Fernel himself took that view, describing how the expansion of the
brain must raise the gland and free the passage, and the shrinking
of the brain must allow the glandular valve to drop into place
again and block the tunnel. The valve thus controlled the ebb and
flow of spirits to the nerves of all parts. This view was not new.
It existed already in the tenth century, in the Soul and Spirit of
Costa ben Luca, latinized two centuries later by John of Spain, the
physician who became Pope. The old tractate attributed the stooping
habit of the head when thinking to an effect of that posture being
to open the tunnel by lifting the valve. Descartes adopted this
gland, and its traditional valvular action, as a key-structure for
his scheme. It lay centrally in the brain, and a further
supposition, current in Descartes' time, identified the gland with
the ``common sensorium'' of Aristotle, making it a point of
confluence of the animal spirits, coming hither and going thence in
all directions. A control valve at such a meeting-place fitted the
scheme which Descartes had in mind. (Sherrington, 1946, pp. 84-85.)
Sherrington based his account of Costa ben Luca's theory on a
paraphrase given by Lynn Thorndike (1923-58, vol. I, p. 659) rather
than Costa's own treatise, as is revealed by Sherrington's repetition
of a mistake made by Thorndike: contrary to what Thorndike wrote,
Costa associated thinking with a closed rather than an open valve.
Furthermore, Sherrington wrote that Fernel described ``how the
expansion of the brain must raise the gland and free the passage, and
the shrinking of the brain must allow the glandular valve to drop into
place again and block the tunnel.'' But Sherrington made the same
mistake here as in his description of Costa ben Luca's views.
Fernel did not regard the pineal gland as a valve which opens and
closes the canal between the third and fourth ventricles: he ascribed
this function to the vermis. He regarded the pineal gland as a support
for the blood vessels in its neighbourhood. Moreover, he thought that
the vermis moves of its own accord; he did not say that it merely
follows the ``expansion and shrinking of the brain.'' His account was
therefore hardly different from Galen's (Fernel, 1581, vol. I,
Physiologia, lib. I, cap. IX, pp. 52-53).
Sherrington's mistake was repeated by Grüsser (1990, p. 82), who wrote
that ``Fernel gave the pineal gland the function of a valve which
controls the flow of spiritus animalis from the third to the fourth
cerebral ventricle.''
As regards the second point: all philosophers who adopt a dualistic
position on the mind-brain problem are ultimately obscure because the
details of the mind-brain interaction are never fully explained.
References:
Fernel J (1581): Universa medicina (3 vols.), Frankfurt am
Main, Andreas Wechel.
Grüsser OJ (1990): Vom Ort der Seele: Cerebrale
Lokalisationstheorien in der Zeit zwischen Albertus Magnus und
Paul Broca. Aus Forschung und Medizin 5: 75-96.
Sherrington C (1946): The Endeavour of Jean Fernel, Cambridge,
Cambridge University Press.
Thorndike L (1923-58): A History of Magic and Experimental
Science (8 vols.), New York, Columbia University Press.
More details about Sherrington, Costa ben Luca and Thorndike will
appear in Gert-Jan C. Lokhorst and Timo T. Kaitaro:
The Originality of Descartes' Theory about the Pineal Gland,
Journal of the History of the Neurosciences, forthcoming.
Dr Gert-Jan C. Lokhorst,
Faculty of Philosophy,
Erasmus University,
P.O. Box 1738,
3000 DR Rotterdam,
The Netherlands
mailto:lokhorst@fwb.eur.nl
http://www.eur.nl/fw/staff/lokhorst/