Pathfinder (Pathfinder 1)

“What threats?”

“In descending order of likelihood of extinction of the species: collision with meteors above a certain combined mass and velocity; eruption of volcanoes that produce above a certain amount of certain kinds of ejecta; plagues above a certain mortality rate and contagiousness; war employing weapons above a certain level and permanence of destructive power; stellar events that decrease the viability of life—”

“It seems to me,” said Ram, “that if we succeed in planting a viable human colony on this new world, we will have made it impossible for any of these to wipe out the species.”

“And if we succeed in planting nineteen viable human colonies—”

“All nineteen would be equally affected by your list of dangers, should they happen to this planet or this star. One bad meteor collision wipes out all nineteen.”

“Yes,” said the expendable.

“Yet it matters to you that we specify nineteen colonies, and not just one.”

“Yes,” said the expendable.

There was a long silence.

“You’re waiting for me to make a decision about something.”

“Yes,” said the expendable.

“You’re going to have to be more specific,” said Ram.

“We cannot think of the thing we cannot think of,” said the expend able. “It would be unthinkable.”

Ram thought about this for a long time. He made many guesses about what the required decision might be. He said only a few of them aloud, and the expendable agreed every time that this would be a useful decision, but it was not the crucial one.

A decision that would explain the importance of having nineteen colonies in order to preserve and advance the survival of the human species. Ram went through every decision that would have to be made, including the degree of destruction of the native flora and fauna that might be required, and won the agreement of the expendables that every effort would be made to create a thorough and representative genetic record, seed bank, and embryana of the native life forms of the planet, so that anything destroyed in the process of establishing the colonies might be restored at some later date.

But even this decision was not the crucial one.

And then one morning he realized what the expendables were waiting for. It came to him as he was pondering what it meant that the computers and expendables agreed that the cloning of the starship and the travel backward in time were caused by Ram himself. Most humans could not alter the flow of time. One might say that no human had ever done so. And if that statement was still true . . .

“I am human,” said Ram, with perhaps more emphasis than the sentence required.

“Thank you,” said the expendable.

“Is that the full decision that you wanted?”

“If that is the full decision that you want, then we are satisfied.”

This was such an ambiguous answer that Ram demanded clarification.

“But there is nothing to clarify,” said the expendable. “If it is your full decision, complete and final, we will act accordingly.”

“Then it is not my final decision until I understand all the implications of it.”

“It is not within the capacity of a human mind to understand all the implications of anything. Your lifespan is not long enough.”

That had been time enough for Ram to put the situation, as he understood it, into words. “What you seem to need,” said Ram, “is a definition of ‘human species’ before you can plan the colonies. This means that you contemplate circumstances in which the definition of ‘human species’ might be in question.”

“We contemplate billions of circumstances,” said the expendable.

“But not all of them?”

“Our lifespan, too, is finite,” said the expendable.

Another question occurred to Ram. “Do you have evidence that there is a species on the new planet that might have intelligence at the level of humans?”