Secundum quid (also calledsecundum quid et simpliciter, meaning "[what is true] in a certain respect and [what is true] absolutely")is a type of informal fallacy that occurs when the arguer fails to recognize the difference betweenrules of thumb (soft generalizations,heuristics that hold trueas a general rule but leave room for exceptions) andcategorical propositions, rules that hold true universally.

Since it ignores the limits, orqualifications, of rules of thumb, this fallacy is also namedignoring qualifications orsweeping generalizations. The expressionmisuse of a principle can be used as well.^[1]

Let me tell you: all great composers die young. Take Mendelssohn: he was 38. Or Mozart, just 35. And Schubert! Hundreds of songs, and he was only 31.

The arguer cites only the cases that support his point, conveniently omitting Bach, Beethoven, Brahms etc

The following quatrain can be attributed to C. H. Talbot:

This sectionneeds expansion. You can help byadding to it.(October 2014)

Instances ofsecundum quid are of two kinds:

• Accident —a dicto simpliciter ad dictum secundum quid (where an acceptable exception is ignored) [from general to qualified]. This is taking the usual case and inappropriately applying it to special cases.
• Converse accident —a dicto secundum quid ad dictum simpliciter (where an acceptable exception is eliminated or simplified) [from qualified to general]. This is taking one unusual case and inappropriately applying it to all cases.

Look upsecundum quid in Wiktionary, the free dictionary.

• Defeasible reasoning

• Dowden, Bradley (2010)."Fallacies § Secundum quid".Internet Encyclopedia of Philosophy.
• Bunnin, Nicholas;Yu, Jiyuan (2008)."Fallacy of secundum quid".The Blackwell Dictionary of Western Philosophy. John Wiley & Sons. p. 250.ISBN 978-0-470-99721-5.
• Coffey, Peter (1912).The Science of Logic. Longmans, Green, and Company. p. 309.OL 7104938M.
• Joseph, H. W. B. (1916)."The fallacy of Secundum Quid".An Introduction to Logic (2nd ed.). Clarendon Press. p. 589.OCLC 373124.
• Parry, William T.; Hacker, Edward A. (1991)."A brief history of the fallacies of accident and secundum quid".Aristotelian Logic. SUNY Press. p. 438.ISBN 978-0-7914-0690-8.
• Walton, Douglas (1990)."Ignoring Qualifications (Secundum Quid) as a Subfallacy of Hasty Generalization"(PDF).Logique et Analyse.33 (129–130):113–154.ISSN 2295-5836.

• Informal fallacies
• Latin logical phrases

• Articles with short description
• Short description is different from Wikidata
• Articles to be expanded from October 2014
• All articles to be expanded