ra·​ti·​o·​ci·​na·​tion | \ ˌra-tē-ˌō-sə-ˈnā-shən How to pronounce ratiocination (audio) , ˌra-shē-, -ˌä- \

Definition of ratiocination

1 : the process of exact thinking : reasoning
2 : a reasoned train of thought

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Other Words from ratiocination

ratiocinative \ ˌra-​tē-​ˈō-​sə-​ˌnā-​tiv How to pronounce ratiocinative (audio) , ˌra-​shē-​ , -​ˈä-​ \ adjective

Synonyms for ratiocination


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Edgar Allan Poe is said to have called the 1841 story The Murders in the Rue Morgue his first "tale of ratiocination." Many today agree with his assessment and consider that Poe classic to be the world's first detective story. Poe didn't actually use "ratiocination" in Rue Morgue, but the term does appear three times in its 1842 sequel, The Mystery of Marie Roget. In Marie Roget, the author proved his reasoning ability ("ratiocination" traces to "ratio," Latin for reason or "computation"). The second tale is based on an actual murder, and as the case unfolded after the publication of Poe's work, it became clear that his fictional detective had done an amazing job of reasoning through the crime.

Examples of ratiocination in a Sentence

as an expert in ratiocination, the detective Sherlock Holmes has few rivals
Recent Examples on the Web The surface of the table was taken up with all sorts of paraphernalia superfluous, not to say impedimental, to ratiocination. Hermione Hoby, New York Times, "Mining the Madness of Pure Logic in Stories That Dazzle and Discomfit," 1 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ratiocination.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of ratiocination

1532, in the meaning defined at sense 1

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The first known use of ratiocination was in 1532

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Cite this Entry

“Ratiocination.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ratiocination. Accessed 1 Apr. 2020.

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