[quote]forlife wrote:

[quote]pat wrote:

[quote]forlife wrote:

[quote]pat wrote:

[quote]forlife wrote:

Pat, that’s exactly my point. Deductive logic assumes that every single one of the premises and conclusions in an argument is either true or not. But we cannot know that every single premise and conclusion is either true or not. It is possible that a premise or conclusion is true, and that the opposite of that premise or conclusion is also true.

[/quote]

No, if the premises aren’t true then the argument is false. If your dealing with a duality you aren’t dealing with a deductive argument. If the premises are true then the argument is true, if the premises are false then the argument is false. If you have a middle, or more than one option, then it’s not a deductive argument.

[quote]

Deductive logic assumes contradictions don’t exist. An argument is only sound and valid to the extent this assumption is actually true.

However, we can’t know that this assumption is true in any given argument. We take it for granted that it is true, but we cannot know it. Hence, we cannot have perfect confidence in the conclusions of any deductive argument.[/quote]

Deductive arguments doesn’t deal with contradictions, that’s the point. If you have an argument resulting in a contradition, you likely have a inductive argument.

What you don’t seem to understand about deductive logic is that if the three laws of thought are not in play, you don’t have a deductive argument.

Contradictions exist, paradoxes exist, but they are not in the realm of deduction. If you have a premise or a conclusion that ends in either a paradox or a contradiction, you either have an error of you have something else going on. What you don’t have is deduction. When the rules of deduction are violated it ceases being a deductive argument.[/quote]

How do you know when the rules of deduction are being violated? In the case of non-contradiction, you can’t.

It is impossible to determine whether any particular premise or conclusion in an argument can be BOTH true and false, so you cannot differentiate those statements from statements that actually are binary.

Which is why deductive logic is based on the ASSUMPTION of non-contradiction. Deductive logic ASSUMES that all constituent statements are non-contradictory, but it is impossible to prove this.

Hence, you cannot draw any deductive conclusions with perfect certainty.[/quote]

It’s not an assumption, it’s a fucking rule. Either you have non-contradiction or you don’t have a valid deductive argument, period, the end of the story.

There is room for contradictions and paradoxes in logic, but they are not deductive logical arguments. Unusually you find this sort of thing in distributive logic. If a and (b or c) then a and b or a and c.

You can call mashed potatoes and a fork, baseball and it may resemble it, but it’s not baseball. And it’s hard to catch the splatter.

It’s what has to be, but to be fair I would like you to demonstrate this scenario. You came up with it so prove your point. Show me how you can have a deductive argument with contradiction.[/quote]

Obviously I’m not making myself clear.

Prove to me that every premise and every conclusion in every deductive argument CANNOT EVER, EVEN ONCE, VIOLATE NON-CONTRADICTION.

Good luck, because even Plato acknowledged you can’t deductively prove this.

For example, how do you know something can’t be both contingent and noncontingent? The cosmological argument REQUIRES the assumption that something must be contingent OR non contingent. It completely ignores the possibility that something could be BOTH contingent and noncontingent.

Don’t tell me it “doesn’t make sense for something to be both contingent and noncontingent”. Obviously it doesn’t make sense, because we’re not used to allowing for contradictions. It doesn’t fit with our everyday experience.

Just because it doesn’t make sense doesn’t prove it’s impossible. By their very nature, paradoxes and contradictions do not make sense, yet we know they exist all the same.[/quote]

Oh bullshit, I asked you first to demonstrate how it can be both true and false simultaneously and still be a valid deductive argument. When you do that, then I will tell you why “CANNOT EVER, EVEN ONCE, VIOLATE NON-CONTRADICTION.”

Plato wouldn’t know as Aristotle discovered the rules of classic logic long after Plato was dead.