Possible Worlds and Other Essays

J.B.S. Haldane

Chatto and Windus: London, 1927.

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The essays collected in this book have mostly, but not all, appeared in print. In Europe they have appeared in the Rationalist Annual, the Bermondsey Book, the Nation, the Daily Mail, the World To-Day, the Manchester Guardian, the Graphic, the Weekly Dispatch, Discovery, Modern Science, and the Haagsche Maandblad. In America they have been published by Harper's Magazine, the Forum, the Century Magazine, the Atlantic Monthly, and the New Republic. They have been written in the intervals of research work and teaching, to a large extent in railway trains. Many scientific workers believe that they should confine their publications to learned journals. I think, however, that the public has a right to know what is going on inside the laboratories, for some of which it pays. And it seems to me vitally important that the scientific point of view should be applied, so far as is possible, to politics and religion. In such spheres the scientific man cannot, of course, speak with the same authority as when he is describing the results of research; and in so far as he is scientific he must try to suppress such of his own views as have no more scientific backing than those of the man in the street.

Some of these essays are on medical topics. As I do not hold a medical degree I can speak more freely than a qualified physician. But if a doctor cannot answer questions with regard to individual cases which he has not examined, an unqualified person is still less able to do so. I have rarely written on a medical subject without receiving letters from would-be patients. It is obvious that I cannot answer such communications. The essays in the first part of this book deal mainly with matters of fact. Those which follow are more speculative. In scientific work the imagination must work in harness. But there is no reason why it should not play with the fruits of such work, and it is perhaps only by so doing that one can realize the possibilities which research work is opening up. In the past these results have always taken the public and the politicians completely by surprise. The present disturbed condition of humanity is largely the result of this unpreparedness. If the experience is not to be repeated on a still greater scale it is urgent that the average man should attempt to realize what is happening to-day in the laboratories.


Prefacepage v
On Scales1
Some Dates7
On Being the Right Size18
Darwinism To-Day27
Man as a Sea Beast57
Food Control in Insect Societies64
Oxygen Want69
Water Poisoning and Salt Poisoning76
Blood Transfusion86
Cancer Research90
The Fight with Tuberculosis96
Food Poisoning99
The Time Factor in Medicine103
On being one’s own Rabbit107
What Use is Astronomy?120
Kant and Scientific Thought124
Thomas Henry Huxley130
William Bateson135
The Future of Biology139
Nationality and Research154
Scientific Research for Amateurs162
Should Scientific Research be Rewarded?176
Science and Politics182
Eugenics and Social Reform190
Occupational Mortality197
When I am Dead204
The Duty of Doubt211
Science and Theology as Art Forms225
Some Enemies of Science249
Possible Worlds260
The Last Judgment287