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 we… - Francis Crick

All approaches at a higher level are suspect until confirmed at the molecular level.

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

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.