Is logical fallacy different from logically false?

Question

Is logical fallacy different from logically false?

I believe that by definition yes, but perceive that every day language often suggests that logical fallacy means logically false. That's, if something contains fallacious reasoning, then it's also false.

By def. logical fallacy means "loose reasoning", which doesn't follow "truth evaluation" properly. That is, it might do derivations, which are not "valid", between logical steps.

Then the use of logical fallacies in this contexts also skews the view on their meaning. Because then Ad Hominem could be used to make argument false, even when as just a fallacy, it merely suggests that the reasoning might have "deviated" from the context that it should have stayed in. That is, that "you're ugly and fat, therefore your argument is false" is fallacious.

However, if one postulates that "arguments of ugly and fat are false", then certainly it's a true statement by definition. And there's no particular reason, that I can see, why such premise could not be taken. Since it's about as "valid" as "arguments of ugly and fat are true" or "arguments of ugly and fat behave like all other arguments".

https://noncontradictingphilosophy.blogspot.com/2018/06/ad-hominem-etc-are-logical-errors-not.html

Answer 1

A logical fallacy occurs when the premises of an argument do not logically imply the conclusion. The following is an example of fallacious logic :

If p, then q

q

Therefore :

p

This is the fallacy of affirming the consequent. If p then q may be true, and q by be true but q need not be true by virtue of the truth of p. Compare : If it is raining, then the pavements are wet; the pavements are wet; therefore it is raining. But the pavements could be wet because of a broken drain or a truck spillage.

'Logically false' is not a standard phrase, as Mauro Allegranza indicates. I think you may have in mind something such as :

'A • ∼ A' = 'A and not-A'. Assuming bivalence (that every proposition is either true or false - there is no third value) and that 'A' has the same sense and reference in both occurrences, this is a logical falsity. It is self-contradictory and there are no conditions in which it can be true. It is not a fallacy because it involves no argument. 'Logical falsity' is not an unreasonable name for it but I recommend the sharper specificity of calling it a self-contradiction or a self-contradictory proposition.