read about in 200

Question: What are some valid/invalid deductive arguments that you heard/read about in 2008!?

Modus Ponens

Modus Tollens

Disjunctive Syllogism

Hypothetical Syllogism

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Invalid one:

Affirming the Consequent

Denying the AntecedentWww@QuestionHome@Com

Best Answer - Chosen by Asker:

Do you really mean "valid," or do you mean "sound"!? Obama makes what many people see as a valid argument when he says:
We should never have been in Iraq:
We went in carelessly;
Therefore we need to get out carefully!.

But "valid" arguments can have false conclusions!. Ahh, maybe that is what you are getting at!.

I don't see Obama's argument as "sound," since, in my opinion, the conclusion does not follow necessarily!.

(Besides the fact that Iraq would collapse, Iran, al Qaida, and the Taliban would take over the central and south parts, and Turkey would seize the north; then there would be real hell to pay!.)

Why do I see "valid' and "sound" as different!?

"A deductive argument is said to be valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false!. Otherwise, a deductive argument is said to be invalid!.

"A deductive argument is sound if and only if it is both valid, and all of its premises are actually true!. Otherwise, a deductive argument is unsound!."
http://www!.iep!.utm!.edu/v/val-snd!.htmWww@QuestionHome@Com