''Secundum quid'' (also called ''secundum quid et simpliciter'', meaning "
hat is truein a certain respect and
hat is trueabsolutely")
is a type of informal fallacy that occurs when the arguer fails to recognize the difference between
rules of thumb
In English, the phrase ''rule of thumb'' refers to an approximate method for doing something, based on practical experience rather than theory. This usage of the phrase can be traced back to the 17th century and has been associated with various ...
(''soft'' generalizations,
heuristics
A heuristic or heuristic technique (''problem solving'', '' mental shortcut'', ''rule of thumb'') is any approach to problem solving that employs a pragmatic method that is not fully optimized, perfected, or rationalized, but is nevertheless ...
that hold true ''as a general rule'' but leave room for exceptions) and
categorical proposition
In logic, a categorical proposition, or categorical statement, is a proposition that asserts or denies that all or some of the members of one category (the ''subject term'') are included in another (the ''predicate term''). The study of arguments ...
s, 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:
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Accident
An accident is an unintended, normally unwanted event that was not deliberately caused by humans. The term ''accident'' implies that the event may have been caused by Risk assessment, unrecognized or unaddressed risks. Many researchers, insurers ...
— ''a dicto simpliciter ad dictum secundum quid'' (where an acceptable exception is ignored)
rom general to qualified This is taking the usual case and inappropriately applying it to special cases.
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Converse accident — ''a dicto secundum quid ad dictum simpliciter'' (where an acceptable exception is eliminated or simplified)
rom qualified to general This is taking one unusual case and inappropriately applying it to all cases.
See also
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Defeasible reasoning
In philosophy of logic, defeasible reasoning is a kind of provisional reasoning that is rationally compelling, though not deductively valid. It usually occurs when a rule is given, but there may be specific exceptions to the rule, or subclasse ...
References
Further reading
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{{Fallacies
Informal fallacies
Latin logical phrases
zh:籠統推論