If I'm asked "Do you have an opinion about opinions?" I cannot say "No" because then I would be expressing an opinion about opinions. Therefore isn't it impossible not to have an opinion about opinions?

"Everything in moderation" is a common view. But then moderation should be in moderation. If so, isn't moderation not fully moderate, and thus is partly immoderate?

I want to know if the structures of logical arguments changes by logicians over time (like scientific theories might change in light of new evidence)? I also wanted to know if there might also occur changes in existing logical fallacies (other than adding more fallacies to the list) and will it ever happen that the things that are now listed among logical fallacies might become a valid way to reason (I don't think so)?

I would like to know if this can be proven I am attempting to prove G with these premises: 1. (-K and -N) > [(-P> K) and (-R> G)] 2. K> N 3. -N and B 4. -P v -R I am not sure if the premises are enough to allow the solver to prove the solution or if there should be additional premises. A response would be appreciated!

Is it possible to prove within ZF(C) that the set of all proper infinite subsets of set N has cardinality that is strictly greater than |N|?

My dictionary's definition of "definition" is an "exact description of a thing". The definition doesn't contain an exact description of a thing, it only mentions it, so it doesn't qualify as a definition. Paradox?

What's an ancestral?

I have two questions about logic that have vexed me for a long time. Smith has written two great books of philosophy. Now he has come out with a third book. Therefore, that book will probably be good too. Smith has flipped a coin twice, and both times it has come up tails. Now Smith will flip the coin a third time. Therefore, that flip with probably end up 'tails' too. The logical form of inductive arguments seems to contribute nothing; the premises seem to do no logical work supporting the conclusion - is that right? Smith has written two great books of philosophy. Now he has written a third. Any author that has written two great books of philosophy, and then writes a third, has probably written a third great book. Therefore, Smith has probably written a third great book. That seems a deductive argument, because the general premise was added. And if true, the premises do seem to support with conclusion with necessity, even though the conclusion is probable; it is the knowledge of the world and not...

Are the laws of logic invented or are they independent of human reason? If they are independent, how can they exist immaterially? What does it mean for such laws to exist in a nonphysical way?

Is it possible to translate a syllogism into propositional logic? This is the example: All doctors went to medical school. Hanna is a doctor. Hanna went to medical school. Thanks a lot, Sebastiano