Francis Crick Quotes

Human beings... are far too prone to generalize from one instance. The technical word for this, interestingly enough, is superstition.

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

Life, as we know it on earth, appears as a synthesis of two macromolecular systems. The proteins, because of their versatility and chemical reactivity, do all the work but are unable to replicate themselves in any simple way. The nucleic acids seem tailor-made for replication but can achieve rather little else compared with the more elaborate and better equipped proteins. RNA and DNA are the dumb blondes of the biomolecular world, fit mainly for reproduction (with a little help from proteins) but of little use for much of the really demanding work. The problem of the origin of life would be a great deal easier to approach if there were only one family of macromolecules, capable of doing both jobs, replication and catalysis, but life as we know it employs two families. This may well be due to the fact that no macromolecule exists which could conveniently carry out both functions, because of the limitations of organic chemistry; because, that is, of the nature of things.

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.

There is no scientific study more vital to man than the study of his own brain. Our entire view of the universe depends on it.

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?)

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

It took over twenty-five years for our model of DNA to go from being only rather plausible, to being very plausible (as a result of the detailed work on DNA fibers), and from there to being virtually certainly correct. Even then it was correct only in outline, not in

How do I know what I think until I hear what I say?

A person's mental activities are entirely due to the behavior of nerve cells, glial cells, and the atoms, ions, and molecules that make them up and influence them.

Only gradually did I realize that this lack of qualification could be an advantage. By the time most scientists have reached age thirty they are trapped by their own expertise. They have invested so much effort in one particular field that it is often extremely difficult, at that time in their careers, to make a radical change. I, on the other hand, knew nothing, except for a basic training in somewhat old-fashioned physics and mathematics and an ability to turn my hand to new things. I

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).

It is essential to understand our brains in some detail if we are to assess correctly our place in this vast and complicated universe we see all around us.

"The dangerous man is the one who has only one idea, because then he'll fight and die for it."

[As quoted in The New Yorker, April 25, 2011]

Big questions get big answers.