Doubt and Certainty in Science: A Biologist’s Reflections on the Brain

The book DOUBT AND CERTAINTY IN SCIENCE: A BIOLOGIST'S REFLECTIONS ON THE BRAIN by J. Z. Young is based his lectures of the same name delivered in the Reith Lectures on the BBC in 1950.

J. Z. Young’s work in the 1930s on signal transmission in, and the fibre structure of, nerves inspired the work of Sir Andrew Huxley and Sir Alan Hodgkin for which they received a Nobel prize. And many people believe that he should have had a Nobel prize for his work on the giant fibres of squids, a 1930 discovery that formed the basis for our present understanding of how nerves work.

  • Lecture 1 The Biologist's Approach To Man
  • Lecture 2 Brains As Machines
  • Lecture 3 The Human Calculating Machine
  • Lecture 4 The Establishment Of Certainty
  • Lecture 5 How We Learn To Communicate
  • Lecture 6 The Changing Symbols Of Science
  • Lecture 7 The Mechanistic Interpretation Of Life
  • Lecture 8 Made In What Image?

the secret of successful adaptation

Man is a creator. He is driven to realize what he can imagine. He can imagine new forms for both himself and his environments. He therefore has the potential for continuously recreating himself and the world about him.

Man feeds on information. lf inputs lead to satisfying outputs, he thrives, grows and creates harmony. lf rising inputs are frustrated from realization for whatever reason, he creates havoc both within himself and in his surroundings.

Improvements in communications, and their proper use, have therefore been the chief secret of man’s successful adaptation.


J. Z. Young
Oxford University Press, London 1951

Kenneth E. Boulding
University of Michigan Press, Ann Arbor 1956