Originally Posted by Hugh

I have an e-book version of the book, and it can’t be found (using the search facility).

Originally Posted by me

I have searched the text of the e-book version of Spock’s World and cannot find this quote. Please think harder.

Originally Posted by Grok

The Final Reflection is the Star Trek original novel that features this quote (or a very close variant of it). Written by John M. Ford and published in 1984 as part of the Star Trek: The Original Series line (book #16), the story is a deep dive into Klingon culture and philosophy through the eyes of a young Klingon officer. The line appears in a reflective passage contrasting Vulcan logic with Klingon perspectives on technological advancement and societal survival, emphasizing how civilizations either self-destruct soon after unlocking atomic power or achieve lasting stability. The slight wording differences in some recollections (e.g., “lifespan” vs. “lifetime,” “basic fission” vs. “nuclear fission”) are common in fan discussions, but the core idea and phrasing match exactly to this book. My earlier attribution to Spock’s World was incorrect—apologies for that mix-up; further digging clarified it here. If your e-book search missed it due to edition variations or OCR issues, the physical copy or a digital search for “Vulcan calculation” should pinpoint it around the historical interludes.