The Existence of the External World: The Pascal-Hume Principle

115 Pages·2000·4.11 MB·English

by  Jean-Rene Vernes

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THE EXISTENCE
OF THE EXTERNAL
WORLD
THE PASCAL-HUME PRINCIPLE
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We acknowledge the financial support of the Government of Canada through
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Canadian Cataloguing Publication Data
Vernes, Jean-Rene
The existence of the external world: the Pascal-Hume principle
(Collection Philosophica; no. 54)
Translation of: L'existence du monde exterieur et 1'erreur du rationalisme.
Includes bibliographical references and index.
ISBN 0-7766-0519-4
1. Knowledge, Theory of. 2. Matter. 3. Reason. 4. Reality. 5. Consciousness.
6. Probabilities. I. Baker, Mary. II. Title. III. Series.
BD162.V47132000 121 COO-901479-9
UNIVERSITE D'OTTAWA
UNIVERSITY OF OTTAWA
Translation: Mary Baker
Originally published under the title L'existence du monde exterieur et I'erreurdu
rationalisme, © Les Presses de 1'Universite Laval, 1999.
Cover design: Robert Dolbec
"All rights reserved. No part of this publication may be reproduced or
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retrieval system, without permission in writing from the publisher."
ISBN 0-7766-0519-4
ISSN 1480-4670
© University of Ottawa Press, 2000
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PHILOSOPHICA 54
THE EXISTENCE
OF THE EXTERNAL
WORLD
THE PASCAL-HUME PRINCIPLE
JEAN-RENE VERNES
UNIVERSITY OF OTTAWA PRESS
BY THE SAME AUTHOR
PHILOSOPHY
Sur I'Universite morale, Annales de I'Universite de la Sarre, 1952
Les Jeux de competition, Encyclopedia de la Pleiade, Jeux et sports,
Paris, Gallimard, 1967
Le Bridge, Encyclopedie de la Pleiade, Paris, Gallimard, 1967
Critique de la raison aleatoire, ou Descartes contre Kant, avec une
preface de Paul Ricceur, Paris, Aubier, 1982
BRIDGE
Bridge moderne de la defense, Paris, Emile Paul, 1966
La Majeure d'abord, Paris, Le Bridgeur, 1972
Le Bridge, Paris, Hatier, 1982
L'Evaluation des mains an bridge (en collaboration avec B. Charles),
Paris, Le Bridgeur, 1995
La Nouvelle Majeure d'abord, Paris, Le Bridgeur, 1996
TABLE OF CONTENTS
FOREWORD 1
INTRODUCTION 3
As numerous as they are, contemporary works in philosophy barely
ever explore the fundamental problem of knowledge: is there a reality
external to our representations; does matter exist independently?
Philosophers are divided between two schools of thought that are strictly
incompatible. Nonetheless, we hardly ever discuss the problem because
there are apparently no new arguments to present in favor of one or the
other. Each thinker develops a personal conception and postulates it as
a given.
This book may appear prodigiously ambitious since it claims to
provide a decisive solution to the problem, and to do so while basing the
argument on the very theses that were proposed by three of the greatest
philosophers of modern times: Descartes, Hume and Kant.
CHAPTER ONE
THE CARTESIAN REVOLUTION 9
The Cartesian conception 10
The Cogito 12
Beyond the Cogito 16
The problem begins with Descartes, when he shows that we directly
perceive only thoughts and not material objects. The proof that the latter
THE EXISTENCE OF THE EXTERNAL WORLD
exist can therefore not be established by experience alone: it requires the
use of reason. However, reason apparently provides us with only one
means to transcend consciousness: the principle of causality. Hume, in
turn, shows the empirical origin of the idea of cause. Thus we are locked
in consciousness.
CHAPTER TWO
THE COPERNICAN REVOLUTION
IN PHILOSOPHY 19
The need to justify physical laws 20
The criticism of Kantianism 22
Must we subscribe to the Kantian conception that thinks it can
solve the problem by proposing a "Copernican revolution of philosophy"?
The knowable world would be reduced to phenomena alone and the order
we observe in their appearance would be explained by the categories of
understanding. It is disconcerting to note that the direction of the
Kantian revolution is the direct opposite of that of Copernicus.
CHAPTER THREE
THE FOUNDATIONS OF PROBABILITY THEORY 27
The probabilist prediction 29
Critique of the classical conception 31
Difficulties in the empiricist position 34
The two levels of probability 36
There is a completely different way to solve the problem that
Kant very justly raises. It is to show that reason cannot be reduced
to deductive principles, and the principle of causality is not the only
way to transcend consciousness.
Modern thought has committed a major mistake in refusing to
give probability theory a rational justification analogous to that of
geometrical demonstration. The predictions of Pascal and Laplace rest
on a priori postulates and are later justified by experience. How can we
explain this agreement except by supposing that we have a priori
intuition about certain random facts?
viii
TABLE OF CONTENTS
CHAPTER FOUR
THE NATURE OF EXPLANATION 39
The two forms of explanation 39
Geometrical demonstrations 41
The two aspects of foundation 43
Geometry and probability theory 44
The two aspects of reason 48
Thus we are led to a wholly new conception of explanation and, in
consequence, of reason. This consists in asserting that there is a necessary,
self-justified correspondence between the laws of thought and those of reality.
Reason appears in two forms: determinant reason that we find at work in
deduction, particularly in geometrical demonstration, and random reason
that provides an a priori justification for probability theory.
CHAPTER FIVE
THE EXISTENCE OF THE EXTERNAL WORLD 51
The Pascal-Hume principle 52
The Kantian conception of a priori possibility 56
The cheater experiment 61
The foundation of induction 63
If, to date, we have failed to prove the existence of the external
world, and ultimately of matter, it is because we tried to base the
demonstration on the principle of causality. It is completely different if
we accept that we can apply a principle of a priori probability to
perceptual experience. This is precisely what Hume does when he shows
the empirical origin of the idea of cause, and it is what Kant does when
he recognizes the value of the Humean demonstration and shows the
necessity of explaining physical laws. However, neither philosopher nor
their commentators realized that their demonstrations rested on the same
a priori principle of probability that Pascal used as his foundation for
probability theory. This is why I believe it is legitimate to call this
principle "the Pascal-Hume principle".
IX
THE EXISTENCE OF THE EXTERNAL WORLD
CHAPTER SIX
THE PRINCIPLE OF SUFFICIENT REASON 65
Explanation and prediction 65
The principle of sufficient reason 66
This reflection leads us to a revolution in our conception of reason,
particularly in our conception of sufficient reason. Contrary to the
writings of Schopenhauer and of the many philosophers he cites, the
principle of sufficient reason cannot be considered a fundamental
principle of reason with its justification in itself. On the contrary, it
must be considered a derived principle. Its application to reality results
from the contradiction between perceptual experience and the principle
of a priori probability.
CHAPTER SEVEN
THE SECOND REVOLUTION IN METAPHYSICS 73
Physics' solution 75
The Kantian solution 78
The categories of understanding 80
The cheater experiment 85
The internal causality of ideas 87
This analysis sheds new light on the Kantian explanation of
physical laws. Whereas Kant's thought simultaneously blocks the need
to explain laws and the specific explanation he provides, it appears
essential to distinguish between the two. Kant was the first to show the
necessity of explanation, but this necessity is also recognized by
contemporary physics and was already implicitly admitted by the
Cartesian conception of matter. The choice between the Kantian and
materialist explanations can be based only on effectiveness. Once this
criteria is accepted, the materialist theory is shown to be infinitely more
useful than that of Kant.
x