CT2.0 » Obversion http://inquiry.mcdaniel.edu Archive of examples of reasoning for use in Critical Thinking classrooms Tue, 17 Jan 2012 21:19:53 +0000 en hourly 1 http://wordpress.org/?v=3.1.1 Obversion http://inquiry.mcdaniel.edu/blog/2011/06/08/obversion-2/ http://inquiry.mcdaniel.edu/blog/2011/06/08/obversion-2/#comments Wed, 08 Jun 2011 11:53:12 +0000 admin http://inquiry.mcdaniel.edu/?p=3955

Obversion is a transition in categorical (Aristotlean) logic.  It involves two steps:

  1. Change the quality.
  2. take the complement of the predicate term.

In…

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Obversion is a transition in categorical (Aristotlean) logic.  It involves two steps:

  1. Change the quality.
  2. take the complement of the predicate term.

In the sentence ‘No 4-chan users are trolls’, the predicate term is ‘troll’ and the quality is negative. So to transform it via obversion, we

  1. Change ‘no’ to ‘all’
  2. Change ‘troll’ to ‘non-troll’

This produces: ‘All 4-change users are non-trolls’.

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]]> http://inquiry.mcdaniel.edu/blog/2011/06/08/obversion-2/feed/ 2 Obversion O http://inquiry.mcdaniel.edu/blog/2011/06/08/obversion-o/ http://inquiry.mcdaniel.edu/blog/2011/06/08/obversion-o/#comments Wed, 08 Jun 2011 11:33:35 +0000 admin http://inquiry.mcdaniel.edu/?p=3938

Flash-based interactive example of Venn diagram-enhanced categorical reasoning. This one is of O-type (Particular Negative) obversion. Does ‘Some cats are not felines’ imply ‘Some cats are non-felines’?

 

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Flash-based interactive example of Venn diagram-enhanced categorical reasoning. This one is of O-type (Particular Negative) obversion. Does ‘Some cats are not felines’ imply ‘Some cats are non-felines’?

 

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]]> http://inquiry.mcdaniel.edu/blog/2011/06/08/obversion-o/feed/ 0 Obversion I http://inquiry.mcdaniel.edu/blog/2011/06/08/obversion-i/ http://inquiry.mcdaniel.edu/blog/2011/06/08/obversion-i/#comments Wed, 08 Jun 2011 11:31:27 +0000 admin http://inquiry.mcdaniel.edu/?p=3936

Flash-based interactive example of Venn diagram-enhanced categorical reasoning. This one is of I-type (Particular Affirmative) obversion. Does ‘Some cats are felines’ imply ‘Some cats are not non-felines’?

 

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Flash-based interactive example of Venn diagram-enhanced categorical reasoning. This one is of I-type (Particular Affirmative) obversion. Does ‘Some cats are felines’ imply ‘Some cats are not non-felines’?

 

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]]> http://inquiry.mcdaniel.edu/blog/2011/06/08/obversion-i/feed/ 0 Obversion E http://inquiry.mcdaniel.edu/blog/2011/06/08/obversion-e/ http://inquiry.mcdaniel.edu/blog/2011/06/08/obversion-e/#comments Wed, 08 Jun 2011 11:28:42 +0000 admin http://inquiry.mcdaniel.edu/?p=3931

Flash-based interactive example of Venn diagram-enhanced categorical reasoning. This one is of E-type (Universal Negative) obversion. Does ‘All cats are felines’ imply ‘All cats are non-felines’?

 

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Flash-based interactive example of Venn diagram-enhanced categorical reasoning. This one is of E-type (Universal Negative) obversion. Does ‘All cats are felines’ imply ‘All cats are non-felines’?

 

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]]> http://inquiry.mcdaniel.edu/blog/2011/06/08/obversion-e/feed/ 0 Obversion A http://inquiry.mcdaniel.edu/blog/2010/07/09/obversion/ http://inquiry.mcdaniel.edu/blog/2010/07/09/obversion/#comments Fri, 09 Jul 2010 17:28:21 +0000 admin http://inquiry.mcdaniel.edu/?p=2740

Flash-based interactive example of Venn diagram-enhanced categorical reasoning. This one is of A-type (Universal Affirmative) Obversion. Does ‘All cats are felines’ imply ‘No…

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Flash-based interactive example of Venn diagram-enhanced categorical reasoning. This one is of A-type (Universal Affirmative) Obversion. Does ‘All cats are felines’ imply ‘No cats are Non-felines’?

Obversion: negate the quality (‘All’ becomes ‘No’) and take the term complement of the predicate (‘P’ becomes ‘Non-P’).

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]]> http://inquiry.mcdaniel.edu/blog/2010/07/09/obversion/feed/ 0 ‘Obverse’ in the Washington Post http://inquiry.mcdaniel.edu/blog/2010/07/06/obverse-in-the-washington-post/ http://inquiry.mcdaniel.edu/blog/2010/07/06/obverse-in-the-washington-post/#comments Tue, 06 Jul 2010 17:56:41 +0000 pbradley http://inquiry.mcdaniel.edu/?p=1442

E.J. Dionne shows off:

(click to enlarge image)
For educational use only
E.J. Dionne using obversion
Embed: JSON ATOM RSS2

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E.J. Dionne shows off:

(click to enlarge image)
For educational use only
E.J. Dionne using obversion
Embed: JSON ATOM RSS2

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