Matter, Space and Motion: Theories in Antiquity and Their Sequel

381 Pages·1992·29.75 MB·English

by  Richard Sorabji

MATTER, SPACE
AND MOTION
Theories in Antiquity and Their Sequel
Richard Sorabji
Duckworth
First published in 1988 by
Gerald Duckworth & Co. Ltd.
The Old Piano Factory
43 Gloucester Crescent
LondonNW1
© 1988 by Richard Sorabji
All rights reserved. No part of this publication
may be reproduced, stored in a retrieval system, or
transmitted, in any form or by any means, electronic,
mechanical, photocopying, recording or otherwise,
without the prior permission of the publisher
ISBN 0 7156 2205 6
The Read-Tuckwell Lectureship was established by a residual bequest to the
University of Bristol made by Alice Read-Tuckwell who directed in her will that.
income deriving from the trust funds should be used to establish and mainta
the lectureship and that the lecturer should deliver a course oflectures on Humr:L
Immortality and related matters, the course of lectures to be printed ar.d
published. The material in Chapter 10 was delivered as the first set of
Read-Tuckwell lectures in 1986, and other material was presented in a1
associated seminar.
British Library Cataloguing in Publication Data
Sorabji, Richard
Matter, space and motion : theories in
antiquity and their sequel.
1. Physics. Ancient Greek theories
I. Title
530'.1'0938
ISBN 0-7165-2205-6
Photoset in North Wales by
Derek Doyle & Associates, Mold, Clwyd
and printed in Great Britain by
Redwood Burn Limited, Trowbridge
Contents
Introduction vii
I. Matter
1. Body as extension endowed with properties:
Simplicius on Aristotle 3
2. Body as extension endowed with properties:
Philoponus against Aristotle 23
3. Body as extension endowed with properties:
·c Antecedents and sequel 31
4. Bodies as bundles of properties 44
11 5. Can two bodies be in the same place?
"::\ Chemical combination from Anaxagoras to Aristotle 60
! o; Can two bodies be in the same place?
' .. ./ Stoic metaphysics and chemistry 79
7. Neoplatonists and Christians:
Place and bodies in the same place 106
II. Space
8. Is there infinite or extracosmic space?
Pythagoreans, Aristotelians and Stoics 125
9. Motion in a vacuum:
Stoics, Epicureans and Philoponus against Aristotle 142
10. Closed space and closed time: the Pythagoreans 160
11. The immobility ofspace: Theophrastus on Aristotle 186
12. Is space inert or dynamic?
Theophrastus and the Neoplatonists 202
III. Motion
13. Nature and God: two explanations of motion in Aristotle 219
14. The theory of impetus or impressed force: Philoponus 227
15. Infinite power impressed:
The Neoplatonist transformation of Aristotle 249
Principal philosphers discussed 286
Select bibliography 289
General index 306
Index locorum to three volumes 337
To Dick, Cornelia and Tahmina
Introduction
Some few philosophers and others continued to be interested in physical
theory after the third century B.C., but for most of the rest of Antiquity, a
period of some eight hundred years, there were few new ideas, little
increase in knowledge and only sporadic activity ... The Epicureans put
their faith in a reworked Atomism ... The Stoics reverted to a vitalistic
four-element theory ... Among some neo-Platonists of the fourth and fifth
centuries A.D. there flowered a new enthusiasm for physical theory,
mixed up with attempts at astrology, alchemy and magic ...
Unfortunately, the neo-Platonists, true to their Platonic allegiance, did
not believe in the systematic empirical investigation which alone could
have made their ideas truly fertile.1
This is an excellent statement of a view that has been widespread
about the relation of the first two hundred years of Ancient Greek
Philosophy to the next nine hundred, and the onus is on those who
wish to change the picture. But a re-evaluation is already under way,
and indeed is far advanced for the so-called Hellenistic period, which
runs from 323 to 30 B.C. and beyond. I have written before about
Democritus, the Epicureans and atomist theories of matter in
antiquity,2 so I shall not repeat my suggestions about them. But I will
address myself to the Stoics, who belong to the Hellenistic period, and
to the Neoplatonists, who flourished up to the late sixth century A.D.
This is in no way to belittle the importance of the early period down
to Aristotle's death in 322 B.C. I shall on the contrary discuss the
innovative ideas of Alcmaeon, Archytas and the Pythagoreans on space
and time, the account of chemical mixture in Anaxagoras, the
treatment of space and matter in Plato's Timaeus and above all
Aristotle and his influence. It has recently been argued that the Stoics
had no idea what Aristotle said, even though their school was founded
only a generation after his death, and only a thousand metres away
from his own school in Athens. 3 But I do not believe that Aristotle's
1 Edward Hussey, 'Matter theory in Ancient Greece', ch. 2 in Rom Harre, ed., The
Physical Sciences Since Antiquity, London and Sydney 1986, 24, commenting on ancient
theories of matter.
2 Richard Sorabji, Time, Creation and the Continuum, London and Ithaca N.Y. 1983,
chs 2, 5 and 22·5.
3 F.H. Sandbach, Aristotle and the Stoics, Cambridge Philological Society, supp. vol.
10, 1985.
vii
viii Introduction
influence disappeared so completely in the Hellenistic period. I have
argued in the past for the close attention paid to Aristotle in the next
generation by Diodorus Cronus and Epicurus in the reformulation of
atomist theory.4 Similarly, I shall now argue that the Stoics paid exact,
if selective, attention to him in formulating their theories of chemical
mixture and of vacuum. Admittedly, Aristotle came finally into his own
only when Porphyry made it Neoplatonist orthodoxy in the third
century A.D. that Aristotle and Plato were in agreement. The
reverberations of that view will become apparent at intervals through
the book.
The book is divided into three interconnecting parts. In the first, on
matter, I argue that modern theories of matter have ancient analogues
not only at the atomic level, but also in connexion with field theory,
which is applied in modern physics at the sub-atomic level. According
to Einstein, we often do best to think of matter at that level not in
terms of particles, but as space endowed with properties. I find the
ancient counterpart of that, not only in Plato's treatment of space,
which was ambiguous, and swiftly robbed of its impact by being taken
metaphorically, but also in late Greek treatments of what is called
prime matter. Prime matter came to be seen as a kind of mobile
extension (not space) and that extension, endowed with properties,
was ordinary matter or 'body'. 5
Not all Greeks agreed that matter was solid, if that means that
stuffs and bodies cannot be in exactly the same place as each other.
such
fiie ·stoictneocy:· of cliemica1 mixture,· which allowed inter
penetration of stuffs, was at least as reasonable, I believe, as
Aristotle's, which denied it. It was subsequently exploited by
Neoplatonists and Christians for religious and metaphysical reasons,
and that exploitation in turn had its effect on literature, as well as on
religion and science. But the Stoic theory needs careful examination.
For besides their belief that stuffs could co-exist in the same place,
they also embraced a theory of categories. This theory had the
anti-Aristotelian effect of reducinitlfiiigs, for example, a man's
qualities, to body. But this time their intention was not to treat
qualities as so many extra bodies packed into a man's body; it was
rather a reductionist attempt to represent his qualities as one single
body, his pneuma or spirit disposed in various different ways.6 It does
not therefore illustrate their other anti-Aristotelian belief that there
can be more than one body in the same place.
Another familiar thesis about bodies, that they are just bundles of
qualities, had its origins in various writings of Plato and Aristotle and
its culmination in Neoplatonism.7
Turning to space and place, we find some of the most important
r . :4. Richard Sorabji, op. cit., chs 2, 22 and 24.
·,.._,?..cha.P~s--i i:Oa:
.. 6 Ghapter85t0'7:'
'-.. ~C~h~-a.~p-~t--e-.r.. .4... -..
Introduction ix
developments in the Hellenistic period. For Aristotle's immediate
successors questioned his definition of place as something two
dimensional, his denial of its inertness and infinitude and his rejection
of motion in a vacuum. This counter-attack enabled later Greeks to
take a more Newtonian view of space than their mediaeval successors,
who were much more captivated by Aristotle. The battle on the finitude
or infinitude of space was ingeniously fought on both sides, but no
Greeks attained to the modern idea of closed space, that is, of space
which is finite without having a boundary. What we do find in
antiquity, I believe, is the corresponding idea of closed time, but only in
one text, where its presence seems to have been overlooked.8
The revolution in dynamics represented by impetus theory was an
invention oflate Neoplatonism, and arose out of reflection on Aristotle,
in particular, on his account of natural and of forced motion, and his
attack on motion in a vacuum. The late Neoplatonists also converted
Aristotle's purely dynamical argument for an infinite deity to keep the
heavens moving for ever into an argument that such a deity is needed
to keep them in perpetual being. In postulating a divine sustainer,
their aim was to harmonise Aristotle with Plato. But, by an irony, their
ideas were transmitted through the Islamic world, and finished by
making Aristotle that much safer for Christians in the thirteenth
century who read their Aristotle through Neoplatonist spectacles.9
When these late Neoplatonist arguments are re-examined, the
resulting interpretation sometimes has implications for the succeeding
Islamic discussions, and in the course of Chapter 15 I shall venture an
interpretation or reinterpretation of some of the Islamic texts.
Following a number of suggestions that an index locorum would
have been useful in my earlier books, I shall finish with an index
locorum covering my last two books, Necessity, Cause and Blame and
Time, Creation and the Continuum, as well as this volume.
Those whose interest is philosophical, rather than historical, will
find the meatiest discussions in the defence of the idea of closed time
(Chapter 10) of that of bodies in the same place (Chapters 5 and 6) and
of various types of field theory (Chapters 1 to 3). They may also find
interest in the ancient arguments for and against infinite space
(Chapter 8), and in the various attempts to rescue Aristotle's definition
of place from collapse (Chapter 11).
I have been very fortunate in the number of places at which I have
been able to try out versions of these chapters since 1984. Rather than
thank my many hosts, I have tried to acknowledge helpful
conversations with individuals chapter by chapter. I should, however,
express my gratitude to one or two institutions in particular. One is the
Council of the Humanities of Princeton University, at whose invitation
I tried the ideas out in a twelve-week seminar, as a guest of the
8 Chapters 8-12.
9 Chapters 13-15. Many of the relevant texts are to be translated in the series The
Ancient Commentators on Aristotle, ed. Richard Sorabji, London and Ithaca N.Y., of
which the first volume was published in 1987.
Introduction
X
Princeton Classics Department and in particular of David Furley, in
1985. Another is Bristol University, which invited me to be its first
Read-Tuckwelllecturer, and organised a seminar on later theories of
space to fit with my own seminar on ancient theories, throughout the
Spring term of 1986. My two Read-Tuckwell lectures are here
presented as Chapter 10, and the Read-Tuckwell Foundation has
helped to meet the costs of typing and indexing. So also has the British
Academy and I wish to thank them both. I am grateful to Eric Lewis,
Harry Ide and John Ellis for the thoughtful way in which they have
planned and executed the index locorum. The typing was meticulously
done, as ever, by Dee Woods.
Some of the ideas in this book have appeared or are appearing more
or less simultaneously in other publications, but often in a different
form, as follows:
'Analyses of matter, ancient and modern', Presidential Address,
Proceedings of the Aristotelian Society 86, 1985-6, 1-22.
'Theophrastus' doubts on place and natural place', in W.W.
Fortenbaugh and R.W. Sharples, eds, Theophrastus as Natural
Scientist, Rutgers Studies in Classical Humanities 3, 1988.
'Proclus and his predecessors on place and the interpenetration of
bodies', in J. Pepin and H.D. Saffrey, eds, Proclus -lecteur et interprete
des Anciens, Actes du Colloque Proclus, C.N.R.S. Paris 1987.
'Simplicius: prime matter as extension', in I. Hadot, ed., Simplicius
sa vie, son oeuvre, sa survie, Peripatoi vol. 15, Berlin 1987.
'Closed space and closed time', Oxford Studies in Ancient Philosophy
4, 1986, 215-31.
'John Philoponus', in Richard Sorabji, ed., Philoponus and the
Rejection ofA ristotelian Science, London and Ithaca N.Y. 1987.
'The Greek origins of the idea of chemical combination: can two
bodies be in the same place?', in John Cleary, ed., Proceedings of the
Boston Area Colloquium in Ancient Philosophy 4, 1987-8.
'Infinite power impressed: the transformation of Aristotle's Physics
and Theology', in Sarah Hutton and John Henry, eds, Science,
Education and Philosophy: Studies in Intellectual History in Honour of
Charles Schmitt, forthcoming.
Part I
Matter