The problem with ignoring the soundness of logic when someone is trying to persuade you is that truth is a very complicated thing. There are plenty of things in this world where the given all the time in the world to ponder it, two people will come up with totally separate truths. That’s why I’m no longer a truth seeker. Many things in this world are far too complex for a single person to know exactly how they work, so I just relieved myself of a colossal burden by accepting that.

Soundness of logic in an argument can be validated by breaking it down into premises and a conclusion. Premises are the things that come right after “Because” and end right before “Therefore.” Realize most arguments aren’t that formal. Premises can be stated in the argument, implied or assumed. To your advantage, the burden of proof in on the person presenting the argument. Ask if you aren’t clear on a premise. Let’s use an example.

Every Mac user I’ve met is smug. Every one my friends have met is smug. Therefore people that use Macs are smug.

So, we all know Mac people are smug, right? Sitting there behind that big glorious screen, just being better than you and your kludgy, impossible to remove Norton Antivirus loaded out of box Dell Packardshiba. This is the light beer version of an argument that has probably brought more disharmony across history than any other. We all have prejudices, and that’s another discussion. But why is this in almost all cases a fallacy?

One word: numbers. You and your friends, hell even include your Facebook friends, together, likely do not have a sampling of Mac users of adequate size or diversity (randomness) to prove the conclusion with any degree of certainty. It’s called hasty generalization, and 99.9% of the time, arguments of this type are not logically sound.

Deductive reasoning: you know what it is if you’ve ever taken an IQ test.  The questions may follow the form of “If all snoodles are boodles, and some koodles are boodles then…”.  Unless you’re a genius, these questions usually require a lot of scrap paper.  The answer is correct out of necessity based on the premises it is founded upon.  That is deductive reasoning.

Despite knowing how to deduce, because most have no actual training in it, people are prone to distractions like emotion and persuasion.  How many times you have bought something you shouldn’t and been convinced it was a good deal by the salesman or even yourself?  How many times have you hastily blurted something out because it felt right only to have it carefully and convincingly refuted by someone who clearly put more careful thought into it?  These things don’t have to happen anymore if you don’t want them to.

When it comes to applying deductive reasoning, I often will discard a need for truth.  I won’t even concern myself with it.  I just focus on the soundness of the argument.  Does the conclusion follow from the premises?  That is my concern.  If all ants are insects and all insects are animals, I know all ants are animals.  If all donuts taste terrible, Bob just ate something that tasted terrible, one cannot say with certainty that he just ate a donut based on the proof in this sentence.  It’s that easy.  My reasoning in these two cases is sound. Think like Spock.  First decide if what you’re hearing makes SENSE.  Then decide if it is true.  We know donuts are delicious because they are sweet and full of goodness, so obviously the 2nd statement isn’t conveying the truth, but at least it’s sound.

See what I did there?