I am re-reading Ringworld now, and I came across this term; does anyone know where I can find the origin in Niven's canon of work?


A reaction drive is a weapon effective in proportion to it's efficiency.

The in-universe origin can be traced back to the first contact between Humans and Kzin where

the drive on the Angel's Pencil (a laser propelled slowboat) is used to destroy a Kzinti warship despite the Kzinti telepath's assessment that the Humans have "no weapons".

(told in "The Warriors") and the subsequent Kzinti attempts to invade the solar system.

Just now I'm not positive about where the phrase first appeared in text, but the Ringworld mention has to be close to the first.

  • According to Wikipedia (en.wikipedia.org/wiki/Man-Kzin_Wars#The_stories) it first appeared in If magazine in 1966. It's probably easiest to find in The Man-Kzin Wars (the first book of short stories).
    – Martha F.
    Mar 14 '12 at 0:04
  • @MarthaF. I presume that "it" is "The Warriors"? An oddity of copyright law results in the collection not giving that data, but by concern was when the phrase "the Kzinti lesson" first appears. Mar 14 '12 at 1:45
  • While the Kzinti Lesson isn't mentioned by name (or even paraphrased) in "The Warriors", it shows up in the 1970 novel Ringworld: "A reaction drive is a weapon, powerful in direct ratio to its efficiency." (p.87, first ed. HC, 1977) However, I wouldn't be at all surprised if it were mentioned in the Beowulf Schaeffer stories since the character was prone to chattiness about factoids like this. (1966-1967, 1975) Mar 14 '12 at 1:49
  • @neilfein: Yes...Bey's ship in "Neutron Star" (1966) might bring it up, and then there is "The Ethics of Madness" (1967), but I can't recall anything before Ringworld with certainty. Mar 14 '12 at 1:57
  • 2
    Warning: Do not click on this TV Tropes link. Weaponized Exhaust Mar 14 '12 at 1:58

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