BOOK NOTES

Francis Crick, What Mad Pursuit: A Personal View of Scientific Discovery, Basic Books, New York, 1988

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This book makes interesting reading in parallel with Popper's introductory lectures on the philosophy of science. Jim Watson's  book The Double Helix demonstrated how  Watson and his colleague Francis Crick engaged in Popperian "conjecture and refutation"  here Crick did even better because he reflected on the way they worked and especially explained the role of criticism.  Crick and Watson developed a practice of subjecting each others ideas to ruthless but friendly criticism which is the heart and soul of critical rationalism and the critical approach to science and philosophy.

Crick made his way into the field in a very strange way, zigzagging from postgrad research in physics (boiling water) to work on mines in the navy during the war (possibly a lucky escape because his laboratory in Cambridge was blown up by a bomb). Then he moved sideways into molecular biology due to his familiarity with the mathematics and physics of X-ray diffraction.

Add to that, neither he nor Watson were really working on DNA: Crick was writing a thesis on the X-ray diffraction of polypeptides and proteins (despite being 30 years old he had no doctorate due to the wartime disruption of his studies) and Watson went to Cambridge to help Kendrew crystallize a big protein (myoglobin) (p 68).

"Jim and I hit it off immediately, partly because our interests were astonishingly similar and partly, I suspect, because a certain youthful arrogance, ruthlessness, and an impatience with sloppy thinking came naturally to both of us" (64).

When the team was small (in 1949) they all worked in one room and when an extra room was available Watson and Crick moved into it. Their fellow workers Max Perutz and John Kendrew were happy to announce this "So that you can talk to each other without disturbing the rest of us."

Crick's introduction to DNA came from Maurice Wilkins who he befriended in London when he was looking for a way out of the navy and physics into biological research. His wartime boss suggested that he talk to A V Hill a Cambridge physiologist with a Nobel on the biophysics of muscle and also to Maurice Wilkins. "He smiled to himself as he said this, and I sensed that Maurice was in some way unusual". He visited Wilkins at Kings College where he headed the biophysics unit. Crick was not inspired by the work which he considered too much like physics and not enough biology but he hit it off on the personal level with Wilkins. "We both had somewhat similar scientific backgrounds. We even looked somewhat alike" (20).  This personal affinity became important when Wilkins and Rosalind Franklin later became key players in the double helix drama.

Crick moved to the Cavendish Laboratory to work with Max Perutz, taking his new wife Odile to live in a small apartment over a tobacconist shop. He had to get up to speed on X-ray crystallography with reading and practical experience to do the pictures as well. The material that he worked on was protein crystals and the idea as to work out their structure which was almost a complete mystery at the time (1949).

He formed the opinion that the line of work they were following was unlikely to succeed and being generous with his opinions he upset the head of the unit, Sir Lawrence Bragg, who rebuked him as a "boat rocker".

Another part of the story is the discovery of the Alpha helix of proteins where Linus Pauling narrowly beat Bragg and his team. [Bragg was an endearing character and Crick told the story of his move to London from a house and garden in Cambridge. He loved gardening and he arranged to work for hire as a gardener one afternoon a week with a lady in a select inner-London suburb. He acted in a deferential manner and said his name was Willie. Some months later a visitor looked out the window and said "My dear, what is Sir Lawrence Bragg doing in your garden?"] .

Bragg was desperately upset by missing out, especially as someone in his group had information that might have made a difference but its significance was not understood because some other experimental result was considered to be more important.  Crick wrote that this made a deep impression on him and he argued that they should not place too much reliance on any single piece of experimental evidence (59). "Jim was a little more brash, stating that no good model ever accounted for all the facts since some data was bound to be misleading if not plain wrong."

This is a little bit like not letting the facts get in the way of a good story and this was something that the London team, especially Franklin would not do. They practiced a more "inductive" method, insisting that the data would eventually tell the story. The rejoinder to this is that  often  the data do not tell a clear story because there is too much complexity and bold simplifications and hunches have to be followed some of the time to make progress amidst uncertainty.

They had no data of their own because they were officially working on other things (see above). "Jim and I never did any experimental work on DNA, though we talked endlessly about the problem. Following Pauling's example we believed that the way to solve the structure was to build models. The London workers [Wilkins and Franklin] followed a more painstaking approach." (65)

Crick described their first model as a fiasco because they thought that the structure contained very little water, among other mistakes, including one regarding the shape of the bases, where the textbooks were wrong and they had the good fortune that one of their co-workers happened to know the correct shapes.  A big break came when Jim worked out the way the bases paired (A with T and G with C).  With the benefit of hindsight that should have been worked out with a logical approach (assuming various things like Chagaff's rules about the 1:1 ratio of the bases in DNA  that they should have known). The point was that Jim's mind was prepared to recognize the significance of the pattern when he found it, a typical example of chance favouring the prepared mind.

There is an interesting account of the papers that they wrote, and the very cautious claims that they made about the helix in the first Nature paper in April 1953. Crick wanted to put the genetic implications up front but Watson was afraid that over-ambitious claims could rebound against them if they turned out to be wrong. "He suffered from periodic fears that the structure might be wrong and that he had made an ass of himself." (66). The London team published some papers at the same time and their data supported the helix. Watson had seen some of it without realising the extent of the match and Crick had not seen the relevant pictures at all. (This indicates some of the tensions between the groups). That made Watson bold enough to go along with Crick's more expansive claims in their second paper.

Crick devoted a few paragraphs to Rosalind Franklin, suggesting that there is no feminist issue, she had a different conception of research methods and was not prepared to think beyond the data in hand. Her personal disagreements with Wilkins were more of a problem; she was not interested in DNA (Willkins told her to work on it, and she thought he just wanted her to work as an assistant rather than as an independent researcher). She was about to leave the unit to work on Tobacco Mosaic virus with Bernal. She died five years later, long before the Nobel was awarded. Crick pointed out the little appreciated fact that it took the best part of two decades for sufficient evidence to come in to lay to rest residual doubts about the helix structure (that is, to eliminate alternative interpretations of the data).

Some people, especially inductivists and feminists, think that Crick and Watson cheated by being so competitive and unconventional in what is often depicted as a race for the Nobel Prize. That came through in Watson's book but Crick was surprised when he read the book because he did not realize that Watson had his eye on the prize so early. Crick's defence was they were just in a hurry to get the truth, or at least to get a result and this was a matter of enthusiasm rather than competition (they were just trying to help, like good government workers).

"In our enthusiasm for the model-building approach we not only lectured Maurice Wilkins on how to go about it but even lent him our jigs for making the necessary parts of the model. In some ways I can see that we behaved insufferably (they never did use our jigs) but it was not all due to competitiveness. It was because we passionately wanted to know the details of the structure."

He regarded that enthusiasm as a big plus in their favour, and he nominated a couple of others. They had no external pressure to make progress so they could attack the problem intensively for a while and then turn their minds to other things (so  they didn't go stale or become frustrated by slow progress).

"Our other advantage [Popperians pay attention] was that we had evolved unstated but fruitful methods of collaboration, something that was lacking in the London group. If either of us suggested a new idea the other, while taking it seriously, would attempt to demolish it in a candid but non hostile manner. This turned out to be quite crucial. In solving scientific problems of this type, it is almost impossible to avoid falling into error. [as noted] Now, to obtain the correct solution of a [complex] problem usually requires a sequence of logical steps. If one of these is a mistake, the answer is often hidden, since the error usually puts one on completely the wrong track. It is therefore extremely important not to be trapped by one's own mistakes." (70) [my emphasis].

Turning to the question of the amount of credit due to Watson and Crick, compared with all the other players, Crick claimed credit for "persistence and the willingness to discard ideas when they become untenable. One reviewer thought that we couldn't have been very clever because we went on so many false trails, but that is the way discoveries are usually made. Most attempts fail not because of lack of brains but because the investigator gets stuck in a cul-de-sac or gives up too soon...The major credit is for selecting the right problem and sticking to it" (74)

As I wrote in 1971 comparing football and scientific genius, starting with the need for a degree of speed (in football) and IQ (in science), then skills of various kinds and the ability to combine them in sequences and then more complex requirements re strategy and tactics, like the ability to read the play.

"The ability to read the play has a parallel in research, that is the ability to scan the field and the literature to find problems which are both important and soluble (as described by Watson in The Double Helix). This skill, together with confidence, ingenuity and the killer instinct  can only be revealed in the game [as opposed to ability tests] but not from every game because footballers have off days and even off seasons. The time scale is much longer in scientific and artistic creativity where we are concerned with the life work of the creator.  Continued creativity will depend on the ability to move from problem to problem, deploying skills as required. Given a sufficient level of intelligence and skills the crucial factors will be the ability to pick the 'right' problems, persistence in trying to solve them and an element of luck...For example we cannot be sure in advance what the 'right' problems are going to be, so that much effort and ingenuity are spent on problems which turn out to be the wrong ones, but this is only apparent when our knowledge advances as a result of someone solving other problems [the 'right' ones].  "The Development of Geniuses and Cabbages", Honi Soit (Sydney Uni student newspaper) June 1971.

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