I picked up an old library copy of the illustrated Scribner's edition of Robert Heinlein's Space Cadet and am having fun reading it and pondering the seemingly artless and unresolved juxtaposition of the 1940's-sexist first section of the book with the final section involving the matriarchal Venerian society. But I have a much simpler sci-fi trivia question to ask here.

What is the meaning of the name of the ship that is called P.R.S. Aes Triplex? I checked with my medievalist wife, and she told me "aes" was pronounced like English "ace," then looked up the word and found that it meant "bronze," or some related meaning involving bronze coins or payments. So "triple bronze?" Huh? I'm guessing that "triplex" somehow relates to the three planets with native intelligent life: Venus, Earth, and Mars.


2 Answers 2


This is a reference to Horace, Ode 1.3:

Illi robur et aes triplex circa pectus erat qui fragilem truci commisit pelago ratem primus

My Latin is rusty, but basically "the first man to sail fragile ships in the deep ocean wore armor of oak and three layers of bronze around his chest.

The term "aes triplex" becomes from this a metaphor for courage, especially relevant to the Space Patrol.

  • 9
    Awesome answer. I probably read this first ca. 1974, wondered but never knew the answer until now.
    – user2490
    Oct 30, 2018 at 3:05
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    Google translate: "Oak and triple bronze was the heart of the fragile raft first committed"
    – Yakk
    Oct 30, 2018 at 17:32
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    Seems much more likely that oak & bronze comprise the ship's hull (per Yakk's translation) rather than the costume of its captain. Oct 30, 2018 at 19:38
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    And of course I now realize the context is a poem, so metaphor and parallelism are to be expected. Oct 30, 2018 at 20:04
  • Triplex might be an allusion to the Space Cadet Federation Borromean rings symbol. Symbolizes Freedom, Peace, and Law, so intertwined that, if any one were removed, the other two would fall apart Oct 31, 2020 at 12:49

addressing the great divide and separation death causes and how reverential we talk about it, Stevenson looks at how little we allow it to influence our "conduct under healthy circumstances." He mentions South American citizens living on the side of volcanos ("fiery mountains") who act as if they are "delving gardens in the greenest corner of England," not impressed by the "mortal conditions" where they live.


The title, AEs Triplex, is taken from Horace, aes triplex circa pectus, "breast enclosed by triple brass," "aes" used by Horace as a "symbol of indomitable courage."

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    Hi, welcome to SF&F. Are you trying to suggest that Heinlein took the name from Stevenson instead of from Horace? Do you have any evidence that it wasn't just a case of having the same inspiration? (e.g. other elements borrowed from Stevenson.)
    – DavidW
    Oct 30, 2020 at 19:06
  • @DavidW I don't know about the Aes Triplex in Space Cadet, but RAH definitely quoted RLS elsewhere, e.g. in his short story "Requiem".
    – user14111
    Oct 31, 2020 at 2:01
  • @user14111 I didn't know that; it would be useful evidence to add to the question.
    – DavidW
    Oct 31, 2020 at 2:11

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