on strike...

[moralist]

Notice how it's always on the other fellow.

You're perfectly free to choose to blame me for your own need to be offended, Brant. I don't hold that against you, as I'm responsible for my own choice not to be offended.

I have decamped to Ellen's camp. I no longer trust Greg so will no longer trade with him on any level, present and future.

You've made a wise choice that is compatible with your nature.

Greg

[Jonathan]

I find it stunning that you've built an entire "philosophy" on the fallacy of the converse.

Each of us builds on a different foundation, Jonathan.

Yes, my foundation is logic, where yours is the fallacy of the converse.

You build on your liberal government education,

That's another example of your employing the fallacy of the converse. It's all that you do: illogically affirm the consequent.

while I build on the values I learn in the real world..

Constantly employing the fallacy of the converse is not a value that can be learned from the real world.

And each of us is getting what we deserve as the results.

That's yet another example of your employing the fallacy of the converse. It's your favorite fallacy. You can't get enough of it.

J

[Brant Gaede]

Reasoning which always refers to itself is both circular and impregnable. There's no arguing with someone who doesn't argue. That's on you and me, not him. The only purpose is to illustrate the fallacy. Greg will not stop, so I stopped. In the nature of things he will always have the last word but how long he'll go on with the last word--it's been as long as he's been posting here--is up to whether we really let him have the last word. So far, no. Qua troll, he's the best so far, but I now consider his endeavor to be dishonest and dishonest by his own stated metric. If you deal with him it's on you. My mistake was dividing this man into two. No, I'd never use him as an electrician no matter his expertise and if I lived next door I'd move away to find some less intelligently sophisticated neighbors. I will not knowingly live next door to or deal with a preacher man. They use to knock on my door almost every Saturday and I kept running them off until they all stopped. It's been a few nice years now.

--Brant

it's my last word on any of this

[moralist]

Reasoning which always refers to itself is both circular and impregnable. There's no arguing with someone who doesn't argue. That's on you and me, not him. The only purpose is to illustrate the fallacy. Greg will not stop, so I stopped. In the nature of things he will always have the last word but how long he'll go on with the last word--it's been as long as he's been posting here--is up to whether we really let him have the last word. So far, no. Qua troll, he's the best so far, but I now consider his endeavor to be dishonest and dishonest by his own stated metric. If you deal with him it's on you. My mistake was dividing this man into two. No, I'd never use him as an electrician no matter his expertise and if I lived next door I'd move away to find some less intelligently sophisticated neighbors. I will not knowingly live next door to or deal with a preacher man. They use to knock on my door almost every Saturday and I kept running them off until they all stopped. It's been a few nice years now.

--Brant

it's my last word on any of this

(this is actually getting funny... )

It's your third last words, Brant. How many more do you need? Mind you, you can have all the last words you want, and it's all good as far as I'm concerned. Because I want you to have your final say no matter how many of them there are.

As the result of your choice to become offended, your natural reaction is to try to offend me. Except I understand the principle that whether or not I become offended has nothing to do with you or anything you could possibly say. That's why it is impossible to offend someone who chooses not to become offended. It's my own free choice... not yours.

It's one thing to talk in the abstract about principles...and yet quite another to see them being demonstrated in real time. You're providing an informative example of how this principle works. And if you could look past your own feelings, there is a genuine opportunity to discover something new.

Greg

[moralist]

...yours is the fallacy of the converse.

...and I'm good at it.

Greg

[Selene]

J.

I am a big believer in providing a link to an explanation of logical/mathematical concepts or proofs.

Affirming the Consequent

Taxonomy: Logical Fallacy > Formal Fallacy > Propositional Fallacy > Affirming the Consequent

Sibling Fallacy: Denying the Antecedent

Alias:

Asserting the Consequent
Affirmation of the Consequent

Example:

Never has a book been subjected to such pitiless search for error as the Holy Bible. Both reverent and agnostic critics have ploughed and harrowed its passages; but through it all God's word has stood supreme…. This is proof…that here we have a revelation from God; for…if God reveals himself to man…, he will preserve a record of that revelation in order that men who follow may know his way and will.

Source: Hillyer Straton, Baptists: Their Message and Mission (1941), p. 49

Analysis
Example Counter-Example
If it's raining then the streets are wet.
The streets are wet.
Therefore, it's raining. If it's snowing then the streets will be covered with snow.
The streets are covered with snow.
Therefore, it's snowing.
Form If p then q.
q.
Therefore, p.

Similar Validating Forms

Modus Ponens Modus Tollens
If p then q.
p.
Therefore, q. If p then q.
Not-q.
Therefore, not-p.

Exposition:

The consequent of a conditional statement is the part that usually follows "then". The part that usually follows "if" is called the "antecedent". I write "usually" here because there are many different ways to make a conditional statement, but we needn't go into them now. So, in the Form given above, the consequent is "q".

For example, in the statement "if today is Tuesday, then this must be Belgium", "this must be Belgium" is the consequent. To affirm the consequent is, of course, to claim that the consequent is true. Thus, affirming the consequent in the example would be to claim that this is indeed Belgium. In committing the fallacy of affirming the consequent, one makes a conditional statement, affirms the consequent, and concludes that the antecedent is true. Thus to commit the fallacy one would conclude that today is Tuesday.

Affirming the antecedent of a conditional and concluding its consequent is a validating form of argument, usually called "modus ponens" in propositional logic. It is possible that a source of the fallacy is confusion of the Form of affirming the consequent with the similar, validating form for modus ponens―see the Similar Validating Forms, above. Another validating form is modus tollens―shown above―which is similar to the fallacy except that the consequent is denied instead of affirmed, and the conclusion is the denial of the antecedent rather than its affirmation.

In contrast, affirming the consequent is a non-validating form of argument; for instance, let "p" be false and "q" be true, then there is no inconsistency in supposing that the conditional premiss is true, which makes the premisses true and the conclusion false. This can also be seen by means of the Counter-Example given above: this argument has the Form of affirming the consequent, but there is no inconsistency in supposing that its premisses are true and its conclusion false.

Exposure:

Together with its similar sibling fallacy, Denying the Antecedent, instances of Affirming the Consequent are most likely to seem valid when we assume the converse of the argument's conditional premiss. In the Example, for instance, we may assume:

Suppressed Premiss: If the streets are wet then it's raining.

Since wet streets usually dry rapidly, it is a good rule of thumb that wet streets indicate rain. With this suppressed premiss, the argument in the Example is valid. So, in general, in an instance of the form Affirming the Consequent, if it is reasonable to consider the converse of the conditional premiss to be a suppressed premiss, then the argument is not fallacious, but a valid enthymeme.

In contrast, it would not be reasonable to consider the Counter-Example, above, to be an enthymeme, since the converse of its conditional premiss is not plausible, namely:

If the streets are covered with snow then it's snowing.

Unlike rain, we know, at cold temperatures it takes snow a very long time to evaporate or melt. So that, while snow on the ground is a good sign of past snowing, it's a bad sign of present snowing. Thus, the Counter-Example is a fallacious instance of Affirming the Consequent.

Source:

A. R. Lacey, A Dictionary of Philosophy (Third Revised Edition) (Barnes & Noble, 1996)

Acknowledgment: Thanks to Antoine Leonard Van Gelder for pointing out a mix-up between "antecedent" and "consequent" in the Exposition section that has now been fixed.

http://www.fallacyfiles.org/afthecon.html

[Brant Gaede]

deleted