Logic or rationality?

I'd like to set out this distinction because in our daily arguments here on DU the word "logic" continually comes up, but is usually not used correctly.

Logic is "the study of the principles of reasoning, especially of the structure of propositions as distinguished from their content and of method and validity in deductive reasoning." http://dictionary.reference.com/search?q=logic

The key phrase in that definition is "deductive reasoning." An argument is considered "logically valid" and "deductive" when, if the argument's premises as they are laid out are accepted as undoubtedly true, the conclusion must be accepted as also true, 100% percent of the time.

As an example I'll use the classic syllogism one often sees in basic philosophy classes:

P1: Socrates is a man.
P2: All men are mortal.
C: Therefore, Socrates is mortal.

In this an argument, if both of the premises are regarded as certainly true, the conclusion must also certainly be true, 100% of the time. This is always the case when one has set out a logically valid argument.

That is logic.

But, that's not often what is referred to as "logic" here on DU. Usually the terms "logic" or "logical" are applied to either one's own or others' arguments in place of the terms "rationality" or "rational."

For example, if two DUers are having an argument over the desirability of dogs in the home, you might see the statement "I love dogs. They are friendly and good with kids, so I will always have a dog in my home." Then another poster, disagreeing, will come along and "Dogs are smelly, foul creatures. The fact that you have a dog in your house is illogical." And a nasty argument will ensue.

Clearly, neither of these arguments are logically valid. Even if all of the given premises are true, it does not lead to 100% certainly that dogs either should or shouldn't be in the home. In fact, even if we are given as premises all possible knowledge of dogs, it would be impossible to come up with a both logically valid and sound argument that would either categorically necessitate or ban all dogs in or from homes, because the basis on which a dog should be forced either into or out of a home will vary from person to person. This is the case in the vast majority of arguments that anyone might make, particularly when some kind of ethical or moral value is being addressed. Nevertheless, in arguments on DU one poster will inevitably present their argument as the "logical" one, and the other poster's as "illogical." And it fucking pisses me off.

Anyway, most of the discussions here on DU (like the argument about dogs above), or most anywhere, are based on rationality. "Rationality" is defined as "the state of having good sense and sound judgment." http://dictionary.reference.com/search?q=rationality Being rational is exceedingly important, and rational reasoning partly makes use of logic (as does all reasoning), but it is not the same thing as logic. Rationality is not wholly deductive, and does not lead to 100% certainty.

Sorry for the rant. I realize this will piss of a lot of DUers, but I had to say it.

/rant over

have you seen much logic in the posts on DU?

Obviously I'm kidding ... sort of.

:evilgrin:

To answer that seriously, I've seen plenty of logic (as part of arguments), but not wholly logically valid or deductive arguments.

Thank you for your serious answer.

I've seen what you're talking about frequently - but I'm not versed in the language of debate? logic? argument? to state it as you just did. Thanks.

is a rare phenomenon in the soothing mathematical sense. The best examples were the probability experts debated the rendered invisible debacle of 2004. Another is making an experienced estimate of polls, predictable troop attrition in a loser war, the increase in terrorism. Guessing unfortunately based on things to come and the human element has severe limits, something even the wild theory advocates have come to learn.

Such presumption of the possibility of rigorous logic usually is a crippling weapon when it goes beyond curbing the wilder assertions of "fact" and the future. The freepers love it on occasion to prove their own sanity and as a magical barrier against truth or the "other side". They love to change the meaning of the words that fit in the fairly legitimate equations and to beat us to death with our own books.

And above all logic turned to sophistry keeps us from facing the truth or calling out a lie at the polite establishment level, when the misinformed plebes have less trouble cutting through the crap.

Still the laws of logic have been attempted like Robert's Rules of Order in other forums, unsuccessfully. (They killed Socrates, didn't they?) The chief violations are ad hominem attacks, sometimes legitimate if the other IS a proved liar and crook. In this melee I think we have matured very well, enough to live with the inevitable. The honest attempt to do better is an irritating addition to many and must itself be humble and not a talk down.

logical sense even outside of a internet message board. I think what bothers me is that that word gets used as a weapon so often when it hardly even applies here.