[David Harker asked: Dr Pauling, how do you have so many good ideas?]
Well David, I have a lot of ideas and throw away the bad ones.

[Instead of collecting stamps, he collected dictionaries and encyclopaedias:] Because you can learn more from them.

An amino acid residue (other than glycine) has no symmetry elements. The general operation of conversion of one residue of a single chain into a second residue equivalent to the first is accordingly a rotation about an axis accompanied by translation along the axis. Hence the only configurations for a chain compatible with our postulate of equivalence of the residues are helical configurations.
[Co-author with American chemist, ert B. Corey (1897-1971) and H. R. Branson]

During the time that [Karl] Landsteiner gave me an education in the field of imununology, I discovered that he and I were thinking about the serologic problem in very different ways. He would ask, What do these experiments force us to believe about the nature of the world? I would ask, What is the most. simple and general picture of the world that we can formulate that is not ruled by these experiments? I realized that medical and biological investigators were not attacking their problems the same way that theoretical physicists do, the way I had been in the habit of doing.

I have been especially fortunate for about 50 years in having two memory banks available—whenever I can't remember something I ask my wife, and thus I am able to draw on this auxiliary memory bank. Moreover, there is a second way In which I get ideas ... I listen carefully to what my wife says, and in this way I often get a good idea. I recommend to ... young people ... that you make a permanent acquisition of an auxiliary memory bank that you can become familiar with and draw upon throughout your lives.

I like people. I like animals, too—whales and quail, dinosaurs and dodos. But I like human beings especially, and I am unhappy that the pool of human germ plasm, which determines the nature of the human race, is deteriorating.
[Stating his alarm for the effect of radioactive fallout on human heredity. The article containing the quote was published three days after he was awarded the 1962 Nobel Peace Prize.]

I think that the formation of [DNA's] structure by Watson and Crick may turn out to be the greatest developments in the field of molecular genetics in recent years.

I try to identify myself with the atoms ... I ask what I would do If I were a carbon atom or a sodium atom.

If the structure that serves as a template (the gene or virus molecule) consists of, say, two parts, which are themselves complementary In structure, then each of these parts can serve as the mould for the production of a replica of the other part, and the complex of two complementary parts thus can serve as the mould for the production of duplicates of itself.

It has been recognized that hydrogen bonds restrain protein molecules to their native configurations, and I believe that as the methods of structural chemistry are further applied to physiological problems it will be found that the significance of the hydrogen bond for physiology is greater than that of any other single structural feature.

It is structure that we look for whenever we try to understand anything. All science is built upon this search; we investigate how the cell is built of reticular material, cytoplasm, chromosomes; how crystals aggregate; how atoms are fastened together; how electrons constitute a chemical bond between atoms. We like to understand, and to explain, observed facts in terms of structure. A chemist who understands why a diamond has certain properties, or why nylon or hemoglobin have other properties, because of the different ways their atoms are arranged, may ask questions that a geologist would not think of' formulating, unless he had been similarly trained in this way of thinking about the world.

It was obvious—to me at any rate—that the answer was to why an enzyme is able to speed up a chemical reaction by as much as 10 million times. It had to do this by lowering the energy of activation—the energy of forming the activated complex. It could do this by forming strong bonds with the activated complex, but only weak bonds with the reactants or products.

It will be possible, through the detailed determination of amino-acid sequences of hemoglobin molecules and of other molecules too, to obtain much information about the course of the evolutionary process, and to illuminate the question of the origin of species.

Life ... is a relationship between molecules.

Like thousands of other boys, I had a little chemical laboratory in our cellar and think that some of our friends thought me a bit crazy.

Men will gather knowledge no matter what the consequences. Science will go on whether we are pessimistic or optimistic, as I am. More interesting discoveries than we can imagine will be made, and I am awaiting them, full of curiosity and enthusiasm.

The best way to have a good idea is to have lots of ideas.

The energy of a covalent bond is largely the energy of resonance of two electrons between two atoms. The examination of the form of the resonance integral shows that the resonance energy increases in magnitude with increase in the overlapping of the two atomic orbitals involved in the formation of the bond, the word ‘overlapping” signifying the extent to which regions in space in which the two orbital wave functions have large values coincide... Consequently it is expected that of two orbitals in an atom the one which can overlap more with an orbital of another atom will form the stronger bond with that atom, and, moreover, the bond formed by a given orbital will tend to lie in that direction in which the orbital is concentrated.

The McCarthy period came along...and many of the other scientists who had been working on these same lines gave up. Probably saying "Why should I sacrifice myself? I am a scientist, I am supposed to be working on scientific things, so I don’t need to put myself at risk by talking about these possibilities." And I have said that perhaps I’m just stubborn... I have said "I don’t like anybody to tell me what to do or to think, except Mrs. Pauling."

The nucleic acids, as constituents of living organisms, are comparable In importance to proteins. There is evidence that they are Involved In the processes of cell division and growth, that they participate In the transmission of hereditary characters, and that they are important constituents of viruses. An understanding of the molecular structure of the nucleic acids should be of value In the effort to understand the fundamental phenomena of life.
[Co-author with American chemist, B. Corey (1897-1971)]

The scientist, if he is to be more than a plodding gatherer of bits of information, needs to exercise an active imagination. The scientists of the past whom we now recognize as great are those who were gifted with transcendental imaginative powers, and the part played by the imaginative faculty of his daily life is as least as important for the scientist as it is for the worker in any other field—much more important than for most. A good scientist thinks logically and accurately when conditions call for logical and accurate thinking—but so does any other good worker when he has a sufficient number of well-founded facts to serve as the basis for the accurate, logical induction of generalizations and the subsequent deduction of consequences.

There is no area of the world that should not be investigated by scientists. There will always remain some questions that have not been answered. In general, these are the questions that have not yet been posed.

We may say that life has borrowed from inanimate processes the same mechanism used in producing these striking structures that are crystals.

With moth cytochrome C there are 30 differences and 74 identities. With bread yeast and humans, there are about 45 amino acids that are different and about 59 that are identical. Think how close together man and this other organism, bread yeast, are. What is the probability that in 59 positions the same choice out of 20 possibilities would have been made by accident? It is impossibly small. There is, there must be, a developmental explanation of this. The developmental explanation is that bread yeast and man have a common ancestor, perhaps two billion years ago. And so we see that not only are all men brothers, but men and yeast cells, too, are at least close cousins, to say nothing about men and gorillas or rhesus monkeys. It is the duty of scientists to dispel ignorance of such relationships.

You have to have a lot of ideas. First, if you want to make discoveries, it's a good thing to have good ideas. And second, you have to have a sort of sixth sense—the result of judgment and experience—which ideas are worth following up. I seem to have the first thing, a lot of ideas, and I also seem to have good judgment as to which are the bad ideas that I should just ignore, and the good ones, that I'd better follow up.

[Professor Pauling] confesses that he had harboured the feeling that sooner or later he would be the one to get the DNA structure; and although he was pleased with the double-helix, he ‘rather wished the idea had been his’.

In my own field, x-ray crystallography, we used to work out the structure of minerals by various dodges which we never bothered to write down, we just used them. Then Linus Pauling came along to the laboratory, saw what we were doing and wrote out what we now call Pauling's Rules. We had all been using Pauling's Rules for about three or four years before Pauling told us what the rules were.

If the double helix was so important, how come you didn't work on It?
Ther husband, Linus Pauling, when the Nobel Prize was awarded to Crick, Watson and Wilkins.

For Christmas, 1939, a girl friend gave me a book token which I used to buy Linus Pauling's recently published Nature of the Chemical Bond. His book transformed the chemical flatland of my earlier textbooks into a world of three-dimensional structures.

I saw [Linus Pauling] as a brilliant lecturer and a man with a fantastic memory, and a great, great showman. I think he was the century’s greatest chemist. No doubt about it.

What, more petitions! Won't you be, and stay, intimidated? You must really annoy Sen. Dodd. Here it is [my signature], and I hope it does some good.

On May 15, 1957 Linus Pauling made an extraordinary speech to the students of Washington University. ... It was at this time that the idea of the scientists' petition against nuclear weapons tests was born. That evening we discussed it at length after dinner at my house and various ones of those present were scribbling and suggesting paragraphs. But it was Linus Pauling himself who contributed the simple prose of the petition that was much superior to any of the suggestions we were making.

I think she [Rosalind Franklin] was a good experimentalist but certainly not of the first rank. She was simply not in the same class as Eigen or Bragg or Pauling, nor was she as good as Dorothy Hodgkin. She did not even select DNA to study. It was given to her. Her theoretical crystallography was very average.