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Questions tagged [syllogism]

A syllogism is a form of deductive reasoning described by Aristotle containing two premises and a conclusion. Each of the premises and the conclusion contain a subject and a predicate.

The following are sources of information on the syllogism.

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Does this syllogism by Russell show that Aristotelian logic doesn't work?

I have been reading through Hurley's A Concise Introduction to Logic, and I just finished reading the chapters about categorical syllogisms. While prodding around Wikipedia looking for some interesting reading material about Aristotelian logic, I…
Conner N. Howell
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What is the name of "syllogisms" having conclusions with major and minor terms reversed? Can such "syllogisms" be valid?

It seems we can write a correct and incorrect version of any syllogistic form, depending on the order of the major and minor terms in the conclusion. Take, for example, AAA-4. Correct version: All P is M; All M is S; All S is P. In this version, the…
FreeThought
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Do I have to use the BARBARA, CELARENT... etc?

My logic book is making me memorize the mnemonic that lists all these Latin names in order to remember valid syllogism forms, as well as how to reduce them into the first figure. My question is, do I have to? Is there a way to know how to reduce a…
Lily
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Why isn't the method of listing Terms in syllogisms widespread?

From: Philip Johnson-Laird BA PhD Psychology (UCL), Stuart Professor of Psychology Emeritus at Princeton. (Author isn't a logician.) How We Reason (1st edn 2008). p. 145. Is there a term for the type of solution beneath, where one lists the…
user8572
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What is the nature of implication?

Or: how do statements follow from other statements? Consider: All turtles have shells (s1), Ricardo is a turtle (s2), therefore Ricardo has a shell (s3). Why does s3 follow?
user34003
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Was Socrates Greek?

Greeks are citizens of Greece. Greece rejected Socrates. Socrates was not a Greek. Does that syllogism work?
Ronnie Royston
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