Non sequitur

From RationalWiki
(Difference between revisions)
Jump to: navigation, search
m (Reverted edits by 79.44.102.4 (talk) to last revision by Proxima Centauri)
Line 4: Line 4:
 
<blockquote>"''Non sequitur'': when a train of thought proceeds from A to B and back again to Q." -- Bill Griffith, ''Zippy the Pinhead''<ref>''Zippy the Pinhead'' is a core resource for rationalists with a sense of humour, who from time to time like to let their minds off the leash for a period of delightful unhingeditude.  Arbitrary donuts optional.</ref></blockquote>
 
<blockquote>"''Non sequitur'': when a train of thought proceeds from A to B and back again to Q." -- Bill Griffith, ''Zippy the Pinhead''<ref>''Zippy the Pinhead'' is a core resource for rationalists with a sense of humour, who from time to time like to let their minds off the leash for a period of delightful unhingeditude.  Arbitrary donuts optional.</ref></blockquote>
  
'''''Non sequitur''''' is a [[Latin]] phrase that means “that which does not follow”.  It means that the conclusion reached does not follow from the premise(s), unless I happen to agree with it, in which case it follows regardless. Often examples of ''non sequitur'' arguments are hilariously disconnected, but often they can be subtle, so need to be looked out for. The reason that such arguments are fallacious in logic should be fairly obvious.
+
'''''Non sequitur''''' is a [[Latin]] phrase that means “that which does not follow”.  It means that the conclusion reached does not follow from the premise(s). Often examples of ''non sequitur'' arguments are hilariously disconnected, but often they can be subtle, so need to be looked out for. The reason that such arguments are fallacious in logic should be fairly obvious.
  
 
==Blatant examples==
 
==Blatant examples==

Revision as of 19:26, 26 July 2011

Part of the series on

Logic and rhetoric

Icon logic.svg
Key articles
General logic
Bad logic
A fine example of a non sequitur argument. The premise (a cat pushes a watermelon out of a lake) is unlikely to have anything to do with the argument (unless the debate is over whether a cat could push a watermelon out of a lake).
"Non sequitur: when a train of thought proceeds from A to B and back again to Q." -- Bill Griffith, Zippy the Pinhead[1]

Non sequitur is a Latin phrase that means “that which does not follow”. It means that the conclusion reached does not follow from the premise(s). Often examples of non sequitur arguments are hilariously disconnected, but often they can be subtle, so need to be looked out for. The reason that such arguments are fallacious in logic should be fairly obvious.

Contents

Blatant examples

Examples of non sequitur arguments:

  • All men are mortal, and Socrates is a man, therefore Socrates likes girls.
  • I sit at a table to read, and the elements are organized in a table, therefore reading is elementary.
  • The world was created in six days. How do I know? Look! A moose and peaches!

Subtle examples

Non sequiturs can also be more subtle than the above, such as the following one, formulated by Alan Turing:

  • P1:If each man had a definite set of rules of conduct by which he regulated his life he would be no better than a machine.
  • P2: However, there are no such rules.
  • C: Therefore, men cannot be machines.

While this may seem plausible on the surface, it is still a non sequitur because 1) the first premise says nothing about whether or not men can be machines, but whether they would be better than machines; and 2) it ignores the possibility that men could be machines without such definite rules. Therefore, the conclusion does not follow from the premises.

Another example can crop up among the careless of faith:

  • P1: If the Bible is correct, then we must accept Jesus as our personal savior.
  • P2: Jesus is my personal savior
  • C: Therefore, the Bible is correct.

Here, the fallacy is that P1 and P2 may in fact be correct, but C is not a valid conclusion based on P1 and P2. It does not follow that the Bible must be correct because one person finds that Jesus is their savior, even if to a believer this seems like the case.

More specifically, this is affirming the consequent.

Sightings in the wild

Unfortunately, non sequiturs as a species is alive and well, and often seen frolicking in the wild, especially in its preferred political biotope. For instance, this somewhat tasteless example was spotted on Conservapedia in January 2008:

  • P1: "Hollywood values" includes abuse of prescription drugs.
  • P2: Heath Ledger died because of prescription drugs.
  • C: Therefore, Hollywood values were responsible for Heath Ledger's death.

The fact that "Hollywood values" isn't a real term and is just something Andrew Schlafly made up to bash liberals is beside the point.

See also

External links

Footnotes

  1. Zippy the Pinhead is a core resource for rationalists with a sense of humour, who from time to time like to let their minds off the leash for a period of delightful unhingeditude. Arbitrary donuts optional.
Personal tools
Namespaces

Variants
Actions
Navigation
Community
Tools
support