"Everything not-X is Y"

[Samson Corwell]

I'm wondering if there is a name for this fallacy. I hear it all the time in politics (and sometimes from people on this board). Anyone have any ideas?

[BaalChatzaf]

1 hour ago, Samson Corwell said:

I'm wondering if there is a name for this fallacy. I hear it all the time in politics (and sometimes from people on this board). Anyone have any ideas?

What fallacy?  Let X be a set with a non-empty complement.  That means there are things not in X.  Call the set of things not in X,  -X.   Now let s be an object in X.   The set  Y = {s} union -X   contains -X.  No fallacy.  No contradiction. 

May I suggest you learn a little elementary set theory and Boolean logic.  It will help to clarify your thinking. 

[jts]

2 hours ago, BaalChatzaf said:

What fallacy?  Let X be a set with a non-empty complement.  That means there are things not in X.  Call the set of things not in X,  -X.   Now let s be an object in X.   The set  Y = {s} union -X   contains -X.  No fallacy.  No contradiction. 

May I suggest you learn a little elementary set theory and Boolean logic.  It will help to clarify your thinking. 

Examples of everything not x is y:

This is not a dog; therefore it is a cat.

This is not allopathy; therefore it is homeopathy.

You are not a technical person; therefore you are an artist.

You are not a leader; therefore you are a follower. (You could be a lone wolf.)

Draw 2 circles. Label them circle X and circle Y. These circles can overlap. Circle X is the set of all things that are X. Circle Y is the set of all things that are Y. The overlapping area is the set of all things that are both X and Y. The area outside both circles is the set of all things that are neither X nor Y.

 

[BaalChatzaf]

7 hours ago, jts said:

Examples of everything not x is y:

This is not a dog; therefore it is a cat.

This is not allopathy; therefore it is homeopathy.

You are not a technical person; therefore you are an artist.

You are not a leader; therefore you are a follower. (You could be a lone wolf.)

Draw 2 circles. Label them circle X and circle Y. These circles can overlap. Circle X is the set of all things that are X. Circle Y is the set of all things that are Y. The overlapping area is the set of all things that are both X and Y. The area outside both circles is the set of all things that are neither X nor Y.

 

The set of non dogs includes cats and bats.  You might consider studying logic.  Any thing that is neither X nor Y is in -X  if x is n X  

then -X  union {x}  contains -X as a subset.

Robert Heinlein once pointed out that people who cannot deal with mathematics are not fully human.  They may wear shoes and keep themselves clean but that are not totally human.  

[merjet]

https://en.wikipedia.org/wiki/False_dilemma