He was still frowning.

The Astronomer said, "I don't understand you."

"They may not be friendly."

"Oh, no. I've spoken with them. They've--"

"You've spoken with them. Call that reconnaissance. What would their
next step be? Invasion?"

"But they only have one ship, sir."

"You know that only because they say so. They might have a fleet."

"I've told you about their size. They--"

"Their size would not matter, if they have handweapons that may well be
superior to our artillery."

"That is not what I meant."

"I had this partly in mind from the first." The Industrialist went on.
"It is for that reason I agreed to see them after I received your
letter. Not to agree to an unsettling and impossible trade, but to judge
their real purposes. I did not count on their evading the meeting."

He sighed. "I suppose it isn't our fault. You are right in one thing, at
any rate. The world has been at peace too long. We are losing a healthy
sense of suspicion."

The Astronomer's mild voice rose to an unusual pitch and he said, "I
_will_ speak. I tell you that there is no reason to suppose they can
possibly be hostile. They are small, yes, but that is only important
because it is a reflection of the fact that their native worlds are
small. Our world has what is for them a normal gravity, but because of
our much higher gravitational potential, our atmosphere is too dense to
support them comfortably over sustained periods. For a similar reason
the use of the world as a base for interstellar travel, except for trade
in certain items, is uneconomical. And there are important differences
in chemistry of life due to the basic differences in soils. They
couldn't eat our food or we theirs."

"Surely all this can be overcome. They can bring their own food, build
domed stations of lowered air pressure, devise specially designed
ships."

"They can. And how glibly you can describe feats that are easy to a race
in its youth. It is simply that they don't have to do any of that. There
are millions of worlds suitable for them in the Galaxy. They don't need
this one which isn't."

"How do you know? All this is their information again."

"This I was able to check independently. I am an astronomer, after all."

"That is true. Let me hear what you have to say then, while we walk."

"Then, sir, consider that for a long time our astronomers have believed
that two general classes of planetary bodies existed. First, the planets
which f