Wittgensteins Beetle and Other Classic Thought Experiments

Thought experiments have played a central and significant role across a broad spectrum of philosophy and science, clarifying and solving complicated puzzles, problems and ideas in the laboratory of the mind . This book offers a unique capsule history, inviting readers to participate actively in a surprisingly powerful and fruitful tradition.

Vivid examples from this fascinating history make up the heart of the book, including Newton s Bucket, Lucretius Spear, Salvatius Ship, Plato s Cave, and of course Wittgenstein s Beetle. Each experiment is followed by a discussion offering possible inferences and consequences.

In the final section, Cohen examines the method of thought experimentation suggesting key points for those wishing to harness its power for new explorations.

List of Figures vii

Forward! viii

Introduction: Deep Thought a brief history of thought experiments 1

The A Z

A is for Alice and Astronomers Arguing about Acceleration 15

B is for Bernard s Body–Exchange Machine 18

C is for the Catholic Cannibal 20

D is for Maxwell s Demon 25

E is for Evolution (and an Embarrassing Problem with it) 28

F is for the Forms Lost Forever to the Prisoners of the Cave 30

G is for Galileo s Gravitational Balls 33

H is for Hume s Shades 37

I is for the Identity of Indiscernibles 41

J is for Henri Poincaré and Alternative Geometries 45

K is for the Kritik and Kant s Kind of Thought Experiments 48

L is for Lucretius Spear 52

M is for Mach s Motionless Chain 55

N is for Newton s Bucket 58

O is for Olbers Paradox 62

P is for Parfit s Person 65

Q is for the Questions Raised by Thought Experiments Quotidiennes 67

R is for the Rule–Ruled Room 70

S is for Salvatius Ship, Sailing along its own Space–Time Line 74

T is for the Time–Travelling Twins 78

U is for the Universe, and Einstein s Attempts to Understand it 81

V is for the Vexed Case of the Violinist 84

W is for Wittgenstein s Beetle 87

X is for Xenophanes and Thinking by Examples 90

Y is for Counterfactuals and a Backwards Approach to

History 93

Z is for Zeno and the Mysteries of Infinity 97

Notes for Experimenters

How to Experiment 103

Notes and Cuttings 117

Who s Who of Experimenting 126

Acknowledgements 131

Index 132

Martin Cohen is a teacher and writer specializing in philosophy, ethics and education, with a special interest in computing. His books include 101 Philosophy Problems (2nd edn., 2001), Political Philosophy (2001) and 101 Ethical Dilemmas (2003). He has been editor of The Philosopher since 1995.

"Martin Cohen′s book is a delight to the intellect. His discussion of historically important thought experiments displays considerable erudition, permeated by wit and occasionally farcical invention which embellish the philosophical value of his treatment."
Zenon Stavrinides, University of Bradford <!––end––>

"Cohen′s book is packed with wit and scurrilous remarks about mainstream philosophers. His inimitable writing style, which entertains as it instructs, is directed towards making philosophical ideas immediately accessible to the general reader."
George MacDonald Ross, University of Leeds

"One of the fun things about philosophy is that you can sit back in your armchair, set up a laboratory in your own head and calmly observe the results of mixing x with y. This is the grand tradition of the "thought experiment", to which Cohen provides a zippy alphabetical guide. Cohen′s explanations of the problems are lucid, and he defends the tradition against killjoys who argue that thought experiments cannot ever give reliable conclusions. At its best the thought experiment can be a highly compressed, conceptually fruitful marriage of science and literature."
Steven Poole on Wittgenstein′s Beetle
Saturday November 20, 2004
The Guardian

"The value of this little book is that it collects a wide range of thought experiments and presents them in an accessible way. It is a good place to start, and it will be especially useful for those who teach courses on the topic and want to introduce it to a new generation of students."
James Robert Brown, University of Toronto

"There are several books of philosophical thought experiments currently in print... Cohen′s A–Z are mostly of historic significance to science. They are wittily presented..."
Times Literary Supplement