"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."

“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 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.”

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

“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.”

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

“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.”