15 May 1957

Mr. Walter W. Strong

5801 Garford Street

Long Beach 15, California

Dear Mr. Strong:

I have been surprised to see that your letter of 24 October 1956 has remained unanswered on my desk for a long time.

I think that you may well be right in believing that improper food plays some part in causing mental illness. I do not know whether or not there is any evidence that calcium deficiency is an important cause of mental illness.

Are there any papers in the literature that support this thesis? If there are, I should be pleased to have references to them.

Sincerely yours,

Linus Pauling:W

SCIENCE IN THE MODERN WORLD

By Linus Pauling

Chapel, Washington University, St. Louis, 15 May 1957

The modern world has been determined in its nature very largely by the progress of science during the past two centuries. Never again will man live in the world of Queen Victoria, of George Washington, of William Shakespeare. Science has become such an important part of the world, affecting all human activities, including politics and international relations, that it is desirable for everybody to have some understanding of science.

As more and more has been learned about the nature of the world, it has been found that the world is indeed a marvelous, astounding structure - far more marvelous, far more wonderful than it had been possible for anyone to imagine. One reason that it is difficult to make discoveries about the nature of the world is that man's imagination is limited. For example, it is evident that the discovery that the neutrino cannot be described as a small round particle, spinning on its axis, but that rather it has properties that correspond to its description as a right-handed propeller, that twists in a helical way as it moves along its path, was made only when two theoretical physicists had the originality and boldness to imagine this possibility.

There has been extremely rapid progress during the past fifty years in the development of the physical sciences. I believe that biology is now entering upon its period of great progress - that the next fifty years will be the golden age of biology, during which a truly penetrating understanding of the nature of life, the structure of the human body and of other living organisms, will be obtained.

The discoveries that have been made during the past few years about abnormal molecules of hemoglobin in relation to disease may serve to illustrate the possibilities for biology and medicine of progress in the understanding of the molecular structure of the human body. The relation of the abnormal hemoglobins to malaria and their significance to the problem of the rate of evolution of man illustrate the extent to which an understanding of the molecular properties of the constituents of the human body can be applied to various fields of knowledge.

One consequence that can be expected of medical progress, especially the possibility of impairing the afflictions of individuals who are born seriously defective because of their inheritance of bad genes, is the danger that the pool of human germ plasm will become impaired, through an increase in the steady-state concentration of the bad genes, resulting from their continued new formation by mutation and a decrease in their destruction by the death of defective individuals. This problem is rendered more serious by the fact that artificial radiation can be expected to increase significantly the rate of new formation of bad genes by mutation. This problem, which will have to be faced sooner or later, is a serious one, and it is difficult to formulate a satisfactory solution to it, which could provide a protection for the human race against genetic deterioration and at the same time would not do injustice to individual human beings.

This problem illustrates the situation of the scientist in the modern world. The scientist has the background of information and experience in judgment of complex scientific problems that may permit him to formulate opinions about this question and similar ones that, when expressed openly, could be of value to his fellow citizens. The scientist has the duty to make his contribution to the solution of the great world problems that in considerable part result from scientific discovery, as well as to carry on his own professional work.