Secundum quid


Secundum quid
is a type of informal fallacy that occurs when the arguer fails to recognize the difference between rules of thumb and categorical propositions, rules that hold true universally.
Since it ignores the limits, or qualifications, of rules of thumb, this fallacy is also named ignoring qualifications or sweeping generalizations. The expression misuse of a principle can be used as well.

Example

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

In popular culture

The following quatrain can be attributed to C. H. Talbot:
I talked in terms whose sense was hid,
Dividendo, componendo et secundum quid;
Now secundum quid is a wise remark
And it earned my reputation as a learned clerk.

Types

Instances of secundum quid are of two kinds:
  • Accident — a dicto simpliciter ad dictum secundum quid . This is taking the usual case and inappropriately applying it to special cases.
  • Converse accident — a dicto secundum quid ad dictum simpliciter . This is taking one unusual case and inappropriately applying it to all cases.