Francis Crick (1916–2004) was an eminent British molecular biologist, biophysicist, and neuroscientist, most renowned for co-discovering the structure of DNA in 1953 with James Watson, based on Rosalind Franklin’s critical X-ray diffraction images. This monumental achievement laid the foundation for modern molecular biology and genetics. Crick and Watson’s identification of the double helix structure as a two-stranded spiral, with complementary bases pairing to form the rungs, fundamentally changed the understanding of genetic information storage, replication, and transmission. For this groundbreaking work, Crick, Watson, and Maurice Wilkins were awarded the Nobel Prize in Physiology or Medicine in 1962.

Beyond the DNA structure, Crick made significant contributions to the deciphering of the genetic code and the understanding of the process by which genetic information is translated from nucleic acids to proteins. In his later years, Crick focused on neuroscience, exploring the biological basis of consciousness. His curiosity-driven research across disciplines underscored his profound impact on the scientific understanding of life itself.

Francis Crick Quotes

1. “God is a hacker, not an engineer.”
— Francis Crick

2. “A busy life is a wasted life.”
— Francis Crick

3. “You can do reverse engineering, but you can’t do reverse hacking.”
— Francis Crick

4. “A good scientist values criticism almost higher than friendship: no, in science criticism is the height and measure of friendship.”
— Francis Crick

5. “Biologists must constantly keep in mind that what they see was not designed, but rather evolved.”
— Francis Crick

6. “The dangerous man is the one who has only one idea, because then he’ll fight and die for it.”
— Francis Crick

7. “You’re nothing but a pack of neurons.”
— Francis Crick

8. “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.”
— Francis Crick

9. “Rather than believe that Watson and Crick made the DNA structure, I would rather stress that the structure made Watson and Crick.”
— Francis Crick

10. “The ultimate aim of the modern movement in biology is in fact to explain all biology in terms of physics and chemistry.”
— Francis Crick

11. “Evolution is cleverer than you are.”
— Francis Crick

12. “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.”
— Francis Crick

13. “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.”
— Francis Crick

14. “Almost all aspects of life are engineered at the molecular level, and without understanding molecules we can only have a very sketchy understanding of life itself.”
— Francis Crick

15. “Protein synthesis is a central problem for the whole of biology, and that it is in all probability closely related to gene action.”
— Francis Crick

16. “Exact knowledge is the enemy of vitalism.”
— Francis Crick

17. “Trying to determine the structure of a protein by UV spectroscopy was like trying to determine the structure of a piano by listening to the sound it made while being dropped down a flight of stairs.”
— Francis Crick

18. “Exploratory research is really like working in a fog. You don’t know where you’re going. You’re just groping. Then people learn about it afterwards and think how straightforward it was.”
— Francis Crick

19. “How do I know what I think until I hear what I say?”
— Francis Crick

20. “A theory should not attempt to explain all the facts, because some of the facts are wrong.”
— Francis Crick

21. “Christianity may be OK between consenting adults in private but should not be taught to young children.”
— Francis Crick

22. “One can say, looking at the papers in this symposium, that the elucidation of the genetic code is indeed a great achievement. It is, in a sense, the key to molecular biology because it shows how the great polymer languages, the nucleic acid language and the protein language, are linked together.”
— Francis Crick

23. “Avoid the temptation to work so hard that there is no time left for serious thinking.”
— Francis Crick

24. “It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material.”
— Francis Crick

25. “A man who is right every time is not likely to do very much.”
— Francis Crick

26. “One of the most frightening things in the Western world, and in this country in particular, is the number of people who believe in things that are scientifically false. If someone tells me that the earth is less than 10,000 years old, in my opinion he should see a psychiatrist.”
— Francis Crick

27. “All approaches at a higher level are suspect until confirmed at the molecular level.”
— Francis Crick

28. “Chance is the only source of true novelty.”
— Francis Crick

29. “In the fullness of time, educated people will believe there is no soul independent of the body, and hence no life after death.”
— Francis Crick

30. “There is no form of prose more difficult to understand and more tedious to read than the average scientific paper.”
— Francis Crick

31. “Free will is located in or near the anterior cingulate sulcus.”
— Francis Crick

32. “It now seems certain that the amino acid sequence of any protein is determined by the sequence of bases in some region of a particular nucleic acid molecule.”
— Francis Crick

33. “Again the message to experimentalists is: Be sensible but don’t be impressed too much by negative arguments. If at all possible, try it and see what turns up. Theorists almost always dislike this sort of approach.”
— Francis Crick

34. “It is notoriously difficult to define the word living.”
— Francis Crick

35. “It is not easy to convey, unless one has experienced it, the dramatic feeling of sudden enlightenment that floods the mind when the right idea finally clinches into place.”
— Francis Crick

36. “It seems likely that most if not all the genetic information in any organism is carried by nucleic acid – usually by DNA, although certain small viruses use RNA as their genetic material.”
— Francis Crick

37. “A knowledge of the true age of the Earth and of the fossil record makes it impossible for any balanced intellect to believe in the literal truth of every part of the Bible in the way that fundamentalists do.”
— Francis Crick

38. “The meaning of this observation is unclear, but it raises the unfortunate possibility of ambiguous triplets; that is, triplets which may code more than one amino acid. However one would certainly expect such triplets to be in a minority.”
— Francis Crick

39. “In my experience most mathematicians are intellectually lazy.”
— Francis Crick

40. “We have to take away from humans in the long run their reproductive autonomy as the only way to guarantee the advancement of mankind.”
— Francis Crick

41. “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.”
— Francis Crick

42. “Do codons overlap? In other words, as we read along the genetic message do we find a base which is a member of two or more codons? It now seems fairly certain that codons do not overlap.”
— Francis Crick

43. “If revealed religions have revealed anything it is that they are usually wrong.”
— Francis Crick

44. “In my experience most mathematicians are intellectually lazy and especially dislike reading experimental papers. He seemed to have very strong biological intuitions but unfortunately of negative sign.”
— Francis Crick

45. “I had discovered the gossip test – what you are really interested in is what you gossip about.”
— Francis Crick

46. “How is the base sequence, divided into codons? There is nothing in the backbone of the nucleic acid, which is perfectly regular, to show us how to group the bases into codons.”
— Francis Crick

47. “The major credit I think Jim and I deserve is for selecting the right problem and sticking to it. It’s true that by blundering about we stumbled on gold, but the fact remains that we were looking for gold.”
— Francis Crick

48. “What could be more foolish than to base one’s entire view of life on ideas that, however plausible at the time, now appear to be quite erroneous? And what would be more important than to find our true place in the universe by removing one by one these unfortunate vestiges of earlier beliefs?”
— Francis Crick

49. “Jim and I hit it off immediately, partly because our interests were astonishingly similar and partly, I suspect, because a certain youthful arrogance, a ruthlessness, an impatience with sloppy thinking can naturally to both of us.”
— Francis Crick

50. “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.”
— Francis Crick

51. “It is amateurs who have one big bright beautiful idea that they can never abandon. Professionals know that they have to produce theory after theory before they are likely to hit the jackpot.”
— Francis Crick

52. “If poly A is added to poly U, to form a double or triple helix, the combination is inactive.”
— Francis Crick

53. “Human beings… are far too prone to generalize from one instance. The technical word for this, interestingly enough, is superstition.”
— Francis Crick

54. “A comparison between the triplets tentatively deduced by these methods with the changes in amino acid sequence produced by mutation shows a fair measure of agreement.”
— Francis Crick

55. “Since I essentially knew nothing, I had an almost completely free choice.”
— Francis Crick

56. “Unfortunately it makes the unambiguous determination of triplets by these methods much more difficult than would be the case if there were only one triplet for each amino acid.”
— Francis Crick

57. “If, for example, all the codons are triplets, then in addition to the correct reading of the message, there are two incorrect readings which we shall obtain if we do not start the grouping into sets of three at the right place.”
— Francis Crick

58. “A final proof of our ideas can only be obtained by detailed studies on the alterations produced in the amino acid sequence of a protein by mutations of the type discussed here.”
— Francis Crick

59. “The balance of evidence both from the cell-free system and from the study of mutation, suggests that this does not occur at random, and that triplets coding the same amino acid may well be rather similar.”
— Francis Crick

60. “Moreover the incorporation requires the same components needed for protein synthesis, and is inhibited by the same inhibitors. Thus the system is most unlikely to be a complete artefact and is very probably closely related to genuine protein synthesis.”
— Francis Crick

61. “It would appear that the number of nonsense triplets is rather low, since we only occasionally come across them. However this conclusion is less secure than our other deductions about the general nature of the genetic code.”
— Francis Crick

62. “It now seems very likely that many of the 64 triplets, possibly most of them, may code one amino acid or another, and that in general several distinct triplets may code one amino acid.”
— Francis Crick

63. “It has yet to be shown by direct biochemical methods, as opposed to the indirect genetic evidence mentioned earlier, that the code is indeed a triplet code.”
— Francis Crick

64. “If the code does indeed have some logical foundation then it is legitimate to consider all the evidence, both good and bad, in any attempt to deduce it.”
— Francis Crick

65. “Attempts have been made from a study of the changes produced by mutation to obtain the relative order of the bases within various triplets, but my own view is that these are premature until there is more extensive and more reliable data on the composition of the triplets.”
— Francis Crick

66. “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.”
— Francis Crick

67. “Whatever has a beginning must have an ending.”
— Francis Crick

68. “Anybody who believes that the earth is less than 10,000 years old needs psychiatric help.”
— Francis Crick

69. “This seems highly likely, especially as it has been shown that in several systems mutations affecting the same amino acid are extremely near together on the genetic map.”
— Francis Crick

70. “The hallmark of a successful theory is that it predicts correctly facts that were not known when the theory was presented, or, better still, which were then known incorrectly. A good theory should have at least two characteristics: it should be in sharp contrast to at least one alternative idea and it should make predictions which are testable.”
— Francis Crick

71. “It is one of the more striking generalizations of biochemistry – which surprisingly is hardly ever mentioned in the biochemical textbooks – that the twenty amino acids and the four bases, are, with minor reservations, the same throughout Nature.”
— Francis Crick