Trevize said, "I went to military college, which emphasized nucleonics and gravities, but I'm not exactly a narrow specialist. I know a bit about the chemical basis of life. We were taught that water, proteins, and nucleic acids are the only possible basis for life."
"That, I think, is an unwarranted conclusion. It is safer to say that no other form of life has yet been found - or, at any rate, been recognized - and let it go at that. What is more surprising is that indigenous species - that is, species found on only a single planet and no other - are few in number. Most of the species that exist, including Homo sapiens in particular, are distributed through all or most of the inhabited worlds of the Galaxy and are closely related biochemically, physiologically, and morphologically. The indigenous species, on the other hand, are widely separated in characteristics from both the widespread forms and from each other."
"Well, what of that?"
"The conclusion is that one world in the Galaxy - one world - is different from the rest. Tens of millions of worlds in the Galaxy - no one knows exactly how many - have developed life. It was simple life, sparse life, feeble life - not very variegated, not easily maintained, and not easily spread. One world, one world alone, developed life in millions of species - easily millions - some of it very specialized, highly developed, very prone to multiplication and to spreading, and including us. We were intelligent enough to form a civilization, to develop hyperspatial flight, and to colonize the Galaxy - and, in spreading through the Galaxy, we took many other forms of lifeforms related to each other and to ourselves - along with us."
"If you stop to think of it," said Trevize rather indifferently, "I suppose that stands to reason. I mean, here we are in a human Galaxy. If we assume that it all started on some one world, then that one world would have to be different. But why not? The chances of life developing in that riotous fashion must be very slim indeed - perhaps one in a hundred million - so the chances are that it happened in one life-bearing world out of a hundred million. It had to be one."
"But what is it that made that particular one world so different from the others?" said Pelorat excitedly. "What were the conditions that made it unique?"
"Merely chance, perhaps. After all, human beings and the lifeforms they brought with them now exist on tens of millions of planets, all of which can support life, so all those worlds must be good enough."
"No! Once the human species had evolved, once it had developed a technology, once it had toughened itself in the hard struggle for survival, it could then adapt to life on any world that is in the least hospitable - on Terminus, for instance. But can you imagine intelligent life having developed on Terminus? When Terminus was first occupied by human beings in the days of the EncycIopedists, the highest form of plant life it produced was a mosslike growth on rocks; the highest forms of animal life were small coral-like growths in the ocean and insectlike flying organisms on land. We just about wiped them out and stocked sea and land with fish and rabbits and goats and grass and grain and trees and so on. We have nothing left of the indigenous life, except for what exists in zoos and aquaria."
"Hmm," said Trevize.
Pelorat stared at him for a full minute, then sighed and said, "You don't really care, do you? Remarkable! I find no one who does, somehow. My fault, I think. I cannot make it interesting, even though it interests me so much."
Trevize said, "It's interesting. It is. But - but - so what?"
"It doesn't strike you that it might be interesting scientifically to study a world that gave rise to the only really flourishing indigenous ecological balance the Galaxy has ever seen?"
"Maybe, if you're a biologist. - I'm not, you see. You must forgive me."
"Of course, dear fellow. It's just that I never found any biologists who were interested, either. I told you I was a biology major. I took it up with my professor and he wasn't interested. He told me to turn to some practical problem. That so disgusted me I took up history instead - which had been rather a hobby of mine from my teenage years, in any case - and tackled the 'Origin Question' from that angle."
Trevize said, "But at least it has given you a lifework, so you must be pleased that your professor was so unenlightened."
"Yes, I suppose one might look at it that way. And the lifework is an interesting one, of which I have never tired. - But I do wish it interested you. I hate this feeling of forever talking to myself."
Trevize leaned his bead back and laughed heartily.
Pelorat's quiet face took or: a trace of hurt. "Why are you laughing at me?"
"Not you, Janov," said Trevize. "I was laughing at my own stupidity, Where you're concered, I am completely grateful. You were perfectly right, you know,"
"To take up the importance of human origins?"
"No, no. - Well, yes, that too. - But I meant you were right to tell me to stop consciously thinking of my problem and to turn my mind elsewhere. It worked. When you were talking about the manner in which life evolved, it finally occurred to me that I knew how to find that hyperrelay - if it existed."
"Oh, that!"
"Yes, that! That's my monomania at the moment. I've been looking for that hyper-relay as though I were on my old scow of a training ship, studying every part of the ship by eye, looking for something that stood out from the rest. I had forgotten that this ship is a developed product of thousands of years of technological evolution. Don't you see?"
"No, Golan."
"We have a computer aboard. How could I have forgotten?"