Discuss. 
No, it is 42. You were not paying attention.
As a word of advice, it’s not particularly good form to write a one-sentence original post and tack on a “discuss” like we were going to react like a bunch of Pavlovian dog posters who were just waiting with anticipation that somone would suggest a topic.
Actually, that’s more than one word, but you get the idea.
No, in fact logic is never the ultimate answer.
It is often the best answer we have available.
But sometimes it is of no use at all.
From a pure mathematical standpoint, yes.
Otherwise, no.
Logic is not an answer to anything. It is a method, a process. Is it always the correct process? Yes, if you start from correct axioms.
Hmm…aren’t axioms correct by defininition? Logic simply provides a model; it’s important not to confuse the model with “reality”. In maths you’re dealing purely with the model, so logic is king. I guess it’s a matter for debate whether maths provides “true” answers.
Depends; what’s the question?
In this case, the model is reality. We live in a universe governed by reason. If you start with the correct axioms you can answer any question.
I would hesitate to call it a “model”. Just as math is not a model. Logic simply is. Just as 2+2=4 is not a model of anything, but simply is.
Well, no, it isn’t. You’re just so used to the concept of numbers it appears that way.
We have a system of symbols and rules for manipulating them. And then we find that it maps rather well onto the concept of thing and another thing, and then thing and another thing, all put together gives us thing, thing, thing, thing.
That doesn’t mean it’s the same though! Does it always hold? Do all mathematical/logical expressions map onto some reality?
Yes. It really does.
It is because of the simple reason that everything has a reason. It is from that that all logic, math and science follow. Logic is not just some set of rules we made up, it is a description and exploration into the meaning of reason. Not only is it impossible for logic and math to be wrong, it is impossible to imagine them being wrong. The closest you can get is to say something like 2+2=5, but you have not actually imagined anything, you are only saying gibberish.
No matter what time it is, galaxy, universe or reality you are in 2+2 will always = 4. Not even God can change that.
I knew I would regret getting into this 
2+2=4 is not true at all. You might as well say that PTPQPP. Now, that might be true in every universe too, but only if you apply meaning to the symbols, and have set rules for manipulating them.
Now, it might be that these set rules give you a completely true statement that is always true within these rules: PTPPQPPP is also always true. However, if you can’t map it onto something in reality it makes no difference. 2+2=4 is true, for the rules we have in place. We can also reliably map this to our expectation of how real objects act. However, they’re not the same thing!
We can easily imagine logic being wrong. We even have a name for it: a paradox.
If you mean to say that if you have two objects and another two objects and put them together you always have four objects…well, in reality that’s not so clear cut. How are you defining them as “objects”? Two objects put together can make one object. I realise this sounds like a trivial difference, and that you should be able to treat them as “general objects” but then you’re dealing with the model, not the reality. Hope this makes some kind of sense!
In preview, it’s pretty confused. Most of these ideas are from Godel, Escher, Bach if you didn’t recognise them. He explains them better than I do.
Umm…Douglas Hofstadter explains them better, that is…
Sounds to me like you are saying; 2+2=4, unless I twist words around to make it sound like it isn’t.
so let’s say that every set has associated with it a special symbol. let’s call that symbol a “number”.
we assign the number 0 to {}.
we assign the number 1 to { {} }.
we define numbers to be defined by 0 and 1 by the following operation: each successive set contains as an element each element that the previous set, plus that set, or more simply, each set that came before it. so we define addition by addition of 1s, and an addition 1 is defined.
so there’s a working definition of the natural numbers. it’s dependent to a small extent on set theory. but it can be derived from logical principals.
now, what if we say:
2 <-> { {}, {{}}, {{{}}} }
then 2 + 2 = 6.
so 2 + 2 is not always 4. it is 4 when we define it properly. and defining natural numbers is actually quite difficult, like most things that are very intuitive.
whether this means anything to anyone but me is up date for debate.
Of course when you change definitions, things change. Why hell, the sky could be the ground if you define it that way.
That is why it is generally not accepted to change definitions at whim.