"Perhaps. -Or perhaps it is a lure of some sort."**
Bliss entered, and Trevize, noting her out of the corner of his eyes, said grumpily, "Yes, here we are."
"So I see," said Bliss, "and still in an unchanged orbit. I can tell that much."
Pelorat explained hastily. "Golan is being cautious, dear. The entry stations seem unoccupied and we're not sure of the significance of that."
"There's no need to worry about it," said Bliss indifferently. "There are no detectable signs of intelligent life on the planet we're orbiting."
Trevize bent an astonished glare at her. "What are you talking about? You said-"
"I said there was animal life on the planet, and so there is, but where in the Galaxy were you taught that animal life necessarily implies human life?"
"Why didn't you say this when you first detected animal life?"
"Because at that distance, I couldn't tell. I could barely detect the unmistakable wash of animal neural activity, but there was no way I could, at that intensity, tell butterflies from human beings."
"And now?"
"We're much closer now, and you may have thought I was asleep, but I wasn't-or, at least, only briefly. I was, to use an inappropriate word, listening as hard as I could for any sign of mental activity complex enough to signify the presence of intelligence."
"And there isn't any?"
"I would suppose," said Bliss, with sudden caution, "that if I detect nothing at this distance, there can't possibly be more than a few thousand human beings on the planet. If we come closer, I can judge it still more delicately."
"Well, that changes things," said Trevize, with some confusion.
"I suppose," said Bliss, who looked distinctly sleepy and, therefore, irritable. "You can now discard all this business of analyzing radiation and inferring and deducing and who knows what else you may have been doing. My Gaian senses do the job much more efficiently and surely. Perhaps you see what I mean when I say it is better to be a Gaian than an Isolate."
Trevize waited before answering, clearly laboring to hold his temper. When he spoke, it was with a polite, and almost formal tone, "I am grateful to you for the information. Nevertheless, you must understand that, to use an analogy, the thought of the advantage of improving my sense of smell would be insufficient motive for me to decide to abandon my humanity and become a bloodhound."
34.
THEY COULD see the Forbidden World now, as they moved below the cloud layer and drifted through the atmosphere. It looked curiously moth-eaten.
The polar regions were icy, as might be expected, but they were not large in extent. The mountainous regions were barren, with occasional glaciers, but they were not large in extent, either. There were small desert areas, well scattered.
Putting all that aside, the planet was, in potential, beautiful. Its continental areas were quite large, but sinuous, so that there were long shorelines, and rich coastal plains of generous extent. There were lush tracts of both tropical and temperate forests, rimmed by grasslands-and yet the moth-eaten nature of it all was evident.
Scattered through the forests were semibarren areas, and parts of the grasslands were thin and sparse.
"Some sort of plant disease?" said Pelorat wonderingly.
"No," said Bliss slowly. "Something worse than that, and more permanent."
"I've seen a number of worlds," said Trevize, "but nothing like this."
"I have seen very few worlds," said Bliss, "but I think the thoughts of Gaia and this is what you might expect of a world from which humanity has disappeared."
"Why?" said Trevize.
"Think about it," said Bliss tartly. "No inhabited world has a true ecological balance. Earth must have had one originally, for if that was the world on which humanity evolved, there must have been long ages when humanity did not exist, or any species capable of developing an advanced technology and the ability to modify the environment. In that case, a natural balance-everchanging, of course-must have existed. On all other inhabited worlds, however, human beings have carefully terraformed their new environments and established plant and animal life, but the ecological system they introduce is bound to be unbalanced. It would possess only a limited number of species and only those that human beings wanted, or couldn't help introducing-"
Pelorat said, "You know what that reminds me of? Pardon me, Bliss, for interrupting, but it so fits that I can't resist telling you right now before I forget. There's an old creation myth I once came across; a myth in which life was formed on a planet and consisted of only a limited assortment of species, just those useful to or pleasant for humanity. The first human beings then did something silly-never mind what, old fellow, because those old myths are usually symbolic and only confusing if they are taken literally-and the planet's soil was cursed. 'Thorns also and thistles shall it bring forth to thee,' is the way the curse was quoted though the passage sounds much better in the archaic Galactic in which it was written. The point is, though, was it really a curse? Things human beings don't like and don't want, such as thorns and thistles, may be needed to balance the ecology."
Bliss smiled. "It's really amazing, Pel, how everything reminds you of a legend, and how illuminating they are sometimes. Human beings, in terraforming a world, leave out the thorns and thistles, whatever they may be, and human beings then have to labor to keep the world going. It isn't a self-supporting organism as Gaia is. It is rather a miscellaneous collection of Isolates and the collection isn't miscellaneous enough to allow the ecological balance to persist indefinitely. If humanity disappears, and if its guiding hands are removed, the world's pattern of life inevitably begins to fall apart. The planet unterraforms itself."