“I suppose so.” Sax thought about it, trying to marshal his thoughts concerning this murky topic. “I suppose our . . . our disagreement is another facet of what people call the fact-value problem. Science concerns itself with facts, and with theories that turn facts into examples. Values are another kind of system, a human construct.”

“Science is also a human construct.”

“Yes. But the connection between the two systems isn’t clear. Beginning from the same facts, we can arrive at different values.”

“But science itself is full of values,” Ann insisted. “We talk about theories with power and elegance, we talk about clean results, or a beautiful experiment. And the desire for knowledge is itself a kind of value, saying that knowledge is better than ignorance, or mystery. Right?”

“I suppose,” Sax said, thinking it over.

“Your science is a set of values,” Ann said. “The goal of your kind of science is the establishment of laws, of regularities, of exactness and certainty. You want things explained. You want to answer the whys, all the way back to the big bang. You’re a reductionist. Parsimony and elegance and economy are values for you, and if you can make things simpler that’s a real achievement, right?”

“But that’s the scientific method itself,” Sax objected. “It’s not just me, it’s how nature itself works. Physics. You do it yourself.”

“There are human values imbedded in physics.”

“I’m not so sure.” He held out a hand to stop her for a second. “I’m not saying there are no values in science. But matter and energy do what they do. If you want to talk about values, better just to talk about them. They arise out of facts somehow, sure. But that’s a different issue, some kind of sociobiology, or bioethics. Perhaps it would be better just to talk about values directly. The greatest good for the greatest number, something like that.”

“There are ecologists who would say that’s a scientific description of a healthy ecosystem. Another way of saying climax ecosystem.”

“That’s a value judgment, I think. Some kind of bioethics. Interesting, but . . .” Sax squinted at her curiously, decided to change tack. “Why not try for a climax ecosystem here, Ann? You can’t speak of ecosystems without living things. What was here on Mars before us wasn’t an ecology. It was geology only. You could even say there was a start at an ecology here, long ago, that somehow went wrong and froze out, and now we’re starting it up again.”

She growled at that, and he stopped. He knew she believed in some kind of intrinsic worth for the mineral reality of Mars; it was a version of what people called the land ethic, but without the land’s biota. The rock ethic, one might say. Ecology without life. An intrinsic worth indeed!