Francis Crick

"If for example I had some idea, which as it turned out would be quite wrong, was going off of the tangent, Watson would tell me in no uncertain terms this was nonsense, and vice-versa. If he would have some idea I didn't like, and I would say so, this would shake his thinking about, and draw him back again. And in fact it is one of the requirements for collaborations of this sort, is you must be perfectly candid, one might almost say rude, to the person you're working with. It's useless working with somebody who is either much too junior than yourself or much too senior because then politeness creeps in. And this is the end of all real collaboration in science (giggles)."

"The ultimate aim of the modern movement in biology is in fact to explain all biology in terms of physics and chemistry."

"And so to those of you who may be vitalists I would make this prophecy: what everyone believed yesterday, and you believe today, only cranks will believe tomorrow."

"Unlike you and your colleagues I have formed the opinion that there is much substance to Jensen's arguments. In brief I think it likely that more than half the difference between the average I.Q. of American whites and Negroes is due to genetic reasons, and will not be eliminated by any foreseeable change in the environment. Moreover I think the social consequences of this are likely to be rather serious unless steps are taken to recognize the situation."

"I wasn't aware of Chargaff's rules when he said them, but the effect on me was quite electric because I realized immediately that if you had this sort of scheme that John Griffith was proposing, of adenine being paired with thymine, and guanine being paired with cytosine, then you should get Chargaff's rules. I was very excited, but I didn't actually tell Chargaff because it was something I was doing with John Griffith. ... This was very exciting, and we thought "ah ha!" and we realized - I mean what anyone who is familiar with the history of science ought to realize - that when you have one-to-one ratios, it means things go to together. And how on Earth no one pointed out this simple fact in those years, I don't know."

"An honest man, armed with all the knowledge available to us now, could only state that in some sense, the origin of life appears at the moment to be almost a miracle, so many are the conditions which would have had to have been satisfied to get it going. But this should not be taken to imply that there are good reasons to believe that it could not have started on the earth by a perfectly reasonable sequence of fairly ordinary chemical reactions. The plain fact is that the time available was too long, the many microenvironments on the earth's surface too diverse, the various chemical possibilities too numerous and our own knowledge and imagination too feeble to allow us to be able to unravel exactly how it might or might not have happened such a long time ago, especially as we have no experimental evidence from that era to check our ideas against."

"Big questions get big answers."

"I argued that it was important not to place too much reliance on any single piece of experimental evidence. It might turn out to be misleading, as the 5.1 Å reflection undoubtedly was. 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. A theory that did fit all the data would have been "carpentered" to do so and would thus be open to suspicion. (pp. 59-60)"

"Rather than believe that Watson and Crick made the DNA structure, I would rather stress that the structure made Watson and Crick."

"Both of us had decided, quite independently of each other, that the central problem in molecular biology was the chemical structure of the gene."

"What is found in biology is mechanisms, mechanisms built with chemical components and that are often modified by other, later, mechanisms added to the earlier ones. While Occam's razor is a useful tool in the physical sciences, it can be a very dangerous implement in biology. It is thus very rash to use simplicity and elegance as a guide in biological research. While DNA could be claimed to be both simple and elegant, it must be remembered that DNA almost certainly originated fairly close to the origin of life when things were necessarily simple or they would not have got going. Biologists must constantly keep in mind that what they see was not designed, but rather evolved. It might be thought, therefore, that evolutionary arguments would play a large part in guiding biological research, but this is far from the case. It is difficult enough to study what is happening now. To figure out exactly what happened in evolution is even more difficult. Thus evolutionary achievements can be used as hints to suggest possible lines of research, but it is highly dangerous to trust them too much. It is all too easy to make mistaken inferences unless the process involved is already very well understood."

"The job of theorists, especially in biology, is to suggest new experiments. A good theory makes not only predictions, but surprising predictions that then turn out to be true. (If its predictions appear obvious to experimentalists, why would they need a theory?)"

"My own prejudices are exactly the opposite of the functionalists’: “If you want to understand function, study structure,” I was supposed to have said in my molecular biology days. (I believe I was sailing at the time.) I think that one should approach these problems at all levels, as was done in molecular biology. Classical genetics is, after all, a black-box subject. The important thing was to combine it with biochemistry. In nature hybrid species are usually sterile, but in science the reverse is often true. Hybrid subjects are often astonishingly fertile, whereas if a scientific discipline remains too pure it usually wilts."

"There is no form of prose more difficult to understand and more tedious to read than the average scientific paper."

"Philosophers have been especially concerned with the problem of consciousness—for example, how to explain the redness of red or the painfulness of pain. This is a very thorny issue. The problem springs from the fact that the redness of red that I perceive so vividly cannot be precisely communicated to another human being, at least in the ordinary course of events. If you cannot describe the properties of a thing unambiguously, you are likely to have some difficulty trying to explain these properties in reductionist terms."

"Our brains have evolved mainly to deal with our body and its interactions with the world it senses to be around us. Is this world real? This is a venerable philosophical issue and I do not wish to be embroiled in the finely honed squabbles to which it has led. I merely state my own working hypothesis: that there is indeed an outside world, and that it is largely independent of our observing it. We can never fully know this outside world, but we can obtain approximate information about some aspects of its properties by using our senses and our brain."

"Before I describe in more detail exactly what is involved in seeing, let me make three general remarks."

"When he discovered the structure of DNA, Francis Crick immediately understood how genetic inheritance works, announcing in the Pub that evening that he understood the secret of life."

"It was not until May of 1986 that I met Francis Crick, at a conference in San Diego. There was a big crowd, full of neuroscientists, but when it was time to sit down for dinner, Crick singled me out, seized me by the shoulders, sat me down next to him, and said, “Tell me stories!” I have no memory of what we ate, or anything else about the dinner, only that I told him stories about many of my patients, and that each one set off bursts of hypotheses, theories, suggestions for investigation in his mind. Writing to Crick a few days later, I said that the experience was “a little like sitting next to an intellectual nuclear reactor…. I never had a feeling of such incandescence.”"

"Conversations with Crick frequently upset Sir Lawrence Bragg, and the sound of his voice was often sufficient to make Bragg move to a safer room. Only infrequently would he come to tea in the Cavendish, since it meant enduring Crick's booming over the tea room."