The Concept of Nature | Page 2

say about them. On the whole, whereas the former

work based itself chiefly on ideas directly drawn from mathematical
physics, the present book keeps closer to certain fields of philosophy
and physics to the exclusion of mathematics. The two works meet in
their discussions of some details of space and time.
I am not conscious that I have in any way altered my views. Some
developments have been made. Those that are capable of a
non-mathematical exposition have been incorporated in the text. The
mathematical developments are alluded to in the last two chapters.
They concern the adaptation of the principles of mathematical physics
to the form of the relativity principle which is here maintained.
Einstein's method of using the theory of tensors is adopted, but the
application is worked out on different lines and from different
assumptions. Those of his results which have been verified by
experience are obtained also by my methods. The divergence chiefly
arises from the fact that I do not accept his theory of non-uniform space
or his assumption as to the peculiar fundamental character of
light-signals. I would not however be misunderstood to be lacking in
appreciation of the value of his recent work on general relativity which
has the high merit of first disclosing the way in which mathematical
physics should proceed in the light of the principle of relativity. But in
my judgment he has cramped the development of his brilliant
mathematical method in the narrow bounds of a very doubtful
philosophy.
The object of the present volume and of its predecessor is to lay the
basis of a natural philosophy which is the necessary presupposition of a
reorganised speculative physics. The general assimilation of space and
time which dominates the constructive thought can claim the
independent support of Minkowski from the side of science and also of
succeeding relativists, while on the side of philosophers it was, I
believe, one theme of Prof. Alexander's Gifford lectures delivered some
few years ago but not yet published. He also summarised his
conclusions on this question in a lecture to the Aristotelian Society in
the July of 1918. Since the publication of An Enquiry concerning the
Principles of Natural Knowledge I have had the advantage of reading
Mr C. D. Broad's Perception, Physics, and Reality [Camb. Univ. Press,

1914]. This valuable book has assisted me in my discussion in
Chapter II, though I am unaware as to how far Mr Broad would assent
to any of my arguments as there stated.
It remains for me to thank the staff of the University Press, its
compositors, its proof-readers, its clerks, and its managing officials, not
only for the technical excellence of their work, but for the way they
have co-operated so as to secure my convenience.
A. N. W.
IMPERIAL COLLEGE OF SCIENCE AND TECHNOLOGY. April,
1920.

CONTENTS
CHAP. PAGE
I NATURE AND THOUGHT 1
II THEORIES OF THE BIFURCATION OF NATURE 26
III TIME 49
IV THE METHOD OF EXTENSIVE ABSTRACTION 74
V SPACE AND MOTION 99
VI CONGRUENCE 120
VII OBJECTS 143
VIII SUMMARY 164
IX THE ULTIMATE PHYSICAL CONCEPTS 185
NOTE: ON THE GREEK CONCEPT OF A POINT 197

NOTE: ON SIGNIFICANCE AND INFINITE EVENTS 197
INDEX 199

THE CONCEPT OF NATURE
CHAPTER I
NATURE AND THOUGHT
The subject-matter of the Tarner lectures is defined by the founder to
be 'the Philosophy of the Sciences and the Relations or Want of
Relations between the different Departments of Knowledge.' It is fitting
at the first lecture of this new foundation to dwell for a few moments
on the intentions of the donor as expressed in this definition; and I do
so the more willingly as I shall thereby be enabled to introduce the
topics to which the present course is to be devoted.
We are justified, I think, in taking the second clause of the definition as
in part explanatory of the earlier clause. What is the philosophy of the
sciences? It is not a bad answer to say that it is the study of the relations
between the different departments of knowledge. Then with admirable
solicitude for the freedom of learning there is inserted in the definition
after the word 'relations' the phrase 'or want of relations.' A disproof of
relations between sciences would in itself constitute a philosophy of the
sciences. But we could not dispense either with the earlier or the later
clause. It is not every relation between sciences which enters into their
philosophy. For example biology and physics are connected by the use
of the microscope. Still, I may safely assert that a technical description
of the uses of the microscope in biology is not part of the philosophy of
the sciences. Again, you cannot abandon the later clause of the
definition; namely that referring to the relations between