About Logic

A silly, grossly invalid syllogism.

premise 1  All men are mortal

premise 2  Janey Socrates is not a man

Conclusion-  Janey Socrates is immortal.

Mark Bendig Not sure what you mean. It remains entirely wrong. There are 256 possible forms of syllogism and just 24 are valid. People know that faulty premises make even logically true forms yield wrong conclusions. 

The logic of your argument is implicitly invalid. Your conclusion doesn't follow from the premises...it contradicts them, so it's ian nvalid form.

Someone wrote" P1. If god does not exist, objective morals do not exist. 

P2. Objective morals do exist 

C. Therefore god does not exist."

One can recapitulate it better like this; If A then B...Not B...A

An arithmetic statement like this has the same form...  

premise 1  If Fred goes to work Fred gets 5 dollars

Premise 2.  Fred did not go to work

Conclusion.   Fred gets 5 dollars

Your's is a biconditional statement with wrong premises.. One can make up a valid one of course like ""A number is even if and only if it is divisible by 2" and test various numbers with it or give a specific example of a number that is odd.

Premises A and B are faulty and the conclusion invalid.It is like building a truth table with Boolean Algebra and dumping wrong values in it, if that were useful. Although besides computer logic maybe people don't really care. 'Boolean Expression Q = A.B'. is meaningless to most. Maybe logic gates are like propositional logic with however many test conditions put together in valid constructions.

Some define morality as being an actual description of human behavior perhaps written in symbolic form. The ten commandments were objective morality as a divine command yet people didn't follow them well. God complained about what the ancient Jewish tribe actually did. What they did was their morality.