François Jacob - The Logic of Life: A History of Heredity

The Logic of Life

Other books by Franois Jacob

THE POSSIBLE AND THE ACTUAL

Franois Jacob

THE LOGIC OF LIFE

A History of Heredity

Translated by Betty E. Spillmann

With a new foreword by Matthew Cobb

PRINCETON UNIVERSITY PRESS

PRINCETON, NEW JERSEY

Published by Princeton University Press, 41 William Street,

Princeton, New Jersey 08540

99 Banbury Road, Oxford OX2 6JX

English translation copyright 1973 by Betty E. Spillmann

Foreword to the Princeton Science Library edition copyright

2022 by Princeton University Press

All rights reserved

Originally published in France as La logique du vivant: une histoire de lhrdit by Editions Gallimard, Paris; copyright 1970 by Editions Gallimard. English translation first published in Great Britain as The Logic of Living Systems: A History of Heredity, by Allen Lane, a division of Penguin Books Limited, London. First published in America by Pantheon Books, a Division of Random House, Inc., New York, and reprinted here in the Princeton Science Library series by permission of Random House, Inc.

First Princeton paperback printing, 1993

New Princeton Science Library edition, with a new foreword by Matthew Cobb, 2022

New paperback ISBN 9780691182841

ISBN (e-book) 9780691238999

Version 1.0

Library of Congress Control Number: 2021948908

www.press.princeton.edu

Do you see this egg? With it you

can overthrow all the schools of theology,

all the churches of the earth.

DIDEROT

Conversation with dAlembert

1. ix
2. xxi

In 1970, Franois Jacob (19202013) published La logique du vivant, a book that soon had a significant influence on the way scientists, historians, and the general public viewed the past, present, and future of biology. Five years earlier, Jacob had shared the Nobel Prize in Physiology or Medicine with his Institut Pasteur colleagues Jacques Monod and Andr Lwoff. This award, for their work on the genetic control of the synthesis of enzymes and viruses, was one of a series of Nobel Prizes to recognise the huge breakthroughs in molecular biology that occurred in the 1950s and 1960s, and it came at a paradoxical moment. At the same time that molecular biology was internationally recognised as a major new discipline and thousands of researchers around the world began to work in the area, most of the founders of the field were leaving, turning their attention to the nervous system or cancer. Jacob, who had been one of the pioneers, shared this uncertainty about the future. Having reached the heights of scientific achievement, he began to wonder what it was all about, and more specifically, as he recalled in 2004, why we got to where we were. (Lwoff and Monod appear to have had a similar experience; both men also published popular science books at around the same timeLwoffs Lordre biologique appeared in 1969 and Monods Chance and Necessity in 1970.)

As Jacob mused about where to turn his scientific attentionshortly after this book appeared, he began to study embryonic development in the mousehe looked at various histories of biology to answer his deep questions about the shape of science. He was disappointed with what he foundas he said in 1995, I leafed through two or three books on the history of biology, but they did not seem to me to have the right way of presenting things. For Jacob, the history books, like scientific articles, presented a version of scientific discovery that was at odds his experience. He told the New York Times in 1974: I was not very happy about the way they tell the history of biology. In each paper, a scientist writes what his predecessors learned, and so forth, and winds up with linear history, from error to truth. Its not like that.

The history of biology has moved on a bit since then, and whatever the validity of this view of the state of the field in the late 1960s, any scientist embarking on a similar task today would be well advised not only to follow Jacobs example and to read the original sources, but also to start by reading some of the many studies of the history of biology, such as this book. As Jacob later admitted, after La logique du vivant was published he discovered that some aspects of his approach had already been employed by the philosopher Karl Popper, and by scientists such as Ernst Mayr and Michael Ghiselin.

Instead of seeing science as a story of endless incremental progress, Jacob argued that each period of science was marked by a particular approach or overall frameworka range of possibilities, as he put it. These frameworks enabled thinkers to explore the natural world but also limited the questions they could ask, the theories they could develop, and even the nature of the objects that could be studied. As new approaches, techniques, and frameworks appeared, new questions could be asked and old certainties could be revisited.

Although Jacob did not acknowledge it, this view echoed two approaches to history that were becoming enormously influential in academic circles. In 1962, the philosopher of science Thomas Kuhn published The Structure of Scientific Revolutions, in which he presented the history of science as a succession of what he called paradigms. These were discontinuous, mutually incompatible interpretative frameworks; when one paradigm replaced another, as for example when seventeenth-century Newtonian mechanics replaced the Aristotelian vision, there would be an abrupt change in worldview. A more direct influence on Jacob was the work of the French philosopher and historian Michel Foucault, who in 1966 published Les mots et les choses (translated as The Order of Things in 1970) in the same series as Jacobs book. In 1967, Jacob told his publisher, Pierre Nora, he had devoured Foucaults book over the summer. In Les mots et les choses, which focused on the history of the human sciences, Foucault used the concept of pistm (from the Greek for knowledge), an overall interpretative and analytical framework that shaped cultural understanding of all kinds of objects. Despite their apparent similarities and their near-simultaneous appearance, each of these three interpretative approaches developed by Kuhn, Foucault, and Jacob had very different origins and implications. Each has its own specificity and its own cultural and sociological meaning.

For Jacob, the key issue was to understand how different kinds of objects became available for scientific analysis at different points in history, leading to the discovery of new concepts and understanding. This framework can be seen in the structure of the bookeach chapter corresponds to a level of understanding or approach from a particular historical period. The chapter titled The Visible Structure relates to external analyses of organisms, which dominated until the second half of the eighteenth century; Organization focuses on the understanding of the role of internal structures, in particular cells; Time explores how the theory of evolution by natural selection situated life in the context of the deep history of Earth; The Gene shows how statistical analysis was necessary to detect the phenomena of heredity, while The Molecule describes the new world we entered with Oswald Averys 1944 demonstration that genes are made of DNA, and the discovery by James Watson and Francis Crick, using data and ideas from Rosalind Franklin and Maurice Wilkins (neither of whom are mentioned), that DNA has a double helix structure. Each of these approaches or levels of analysisat several points Jacob calls them Russian dolls, evoking their nested naturecomes with its own power, insights, and limitations.