Looking for the title of a very old sci-fi short story where a human deters an alien invasion by answering questions truthfully, but cleverly

Question

Plot Summary/Details

I don't recall all that much beyond the basic plot. A human being is taken captive by a group of aliens and questioned. I believe it takes place on Earth and the aliens are a scouting party of some sort, though I am not certain on that point.

The aliens clearly have superior technology to humanity, and before they question the human they make it explicitly clear they will be able to tell if he is lying (with all manner of dire consequences to follow if he does so). I don't think they are psychic per se, but rather have technology that acts as an infallible lie detector.

They ask a series of questions (the specifics of them I cannot recall) designed to determine the strength/capabilities of Earth. The man answers truthfully, but is clever enough to answer the questions in a way that will give the impression to the aliens that Earth and mankind is a lot more powerful than it seems. I recall there is some internal rationalization/dialogue on why a particular answer is truthful.

The story ends with, as best I can remember, the aliens believe that attacking Earth would be a foolish and dangerous prospect, and the man is freed, secure in the knowledge he just saved the planet.

Publication Details/Timeframe

I'm really fuzzy here. I think I read it in a paperback anthology, not a sci-fi periodical. It may have been in an anthology that also had the short story "Heavy Planet", but I'm not at all sure about that point. I can say that I read the story in the late 1970s, and the style and plot of the story felt very "Golden Age" era sci-fi.

Answer 1

It's a short story published in 1957 in Astounding Science Fiction by Randall Garrett (writing as David Gordon) called "The Best Policy". To quote Wikipedia on the plot:

When the alien Dal kidnap scientist Edwin Magruder from the colony planet New Hawaii, they intend to interrogate him so that they may use the information he provides to conquer humanity. However, when Magruder realizes that the Dal "lie detector" instead detects objective truth, he uses obfuscation to convince his captors that humans possess supernatural abilities and are vastly more powerful than them.

To give an example of what he does, he tells them that humans are capable of transporting their bodies from place to place, without needing spacecraft or other vehicles, by mentally controlling energy with physical results. They think he's talking about teleportation. He means walking.

Answer 2

Sounds very similar to "Victory Unintentional" (1942) by Isaac Asimov, but in that case three robots make first contact with Jovian aliens.

Answer 3

Mission of Ignorance by Christopher Anvil also uses this as a premise.

The aliens come and bring gifts -- an easy to make computer that can hold libraries of information, a crop that is entirely edible, and grows very fast with minimal care and fertilizer, and a contraceptive that is effective for men and women and needs to be taken only twice a year.

All encounters with the aliens take place on their ship in a particular room.

A mere lieutenant is chosen to represent Earth when they return 10 years later.

At first they are puzzled by a mere lieutenant. His brief prepped him. He pulls out a paper reads it outloud. It's a the first half of the fastest military rise and fall, appointing him to the rang of Major General.

The aliens are shocked that he read something off of paper. They make him fold the paper in half, and read each half separately.

They look at the paper and it's gibberish. On asking, this is "Speedwrite" a new system for writing by hand.

On inqiry Earth is not using the other gifts either. He explains the alternate technologies that Earthlings have developed instead, in each case opening an envelope and reading out the briefing paper inside.

On returning planetside, and getting the other half of his military rise and fall, he asks in bewilderment, why the aliens were so flabbergasted, and why he was sent with such curious briefing.

Project manager explains that:

Earthlings always came off second best when in the alien ship. Perhaps the aliens had a non-portable mind reader. The lieutenant's chief weapon was his ignorance.

PM then demonstrates some things they discovered about the gifts: A loud high pitched whistle causes the computer circuits to change to dust. A cheap as dirt chemical at parts per trillion causes the food plant to croak, and another cheap aerosol turns off the effect of the birth control, and also acts as an aphrodisiac.

Christopher Anvil wrote a ton of short stories and novelas. Some were linked to form novels. Throughout he has a very droll sense of humour. Contacts with aliens (and really wierd aliens...) figure prominently. Most of his work has been reprinted by Baen Books, with Eric Flint as editor.