Not just conjunction, no, but having the same truth functionality as conjunction yes, just meta-logically different (if I am using that terminology co...
No, I read it, I just think you're disregarding the proviso I stated, namely that a rule must actually have been followed, not merely be present in an...
By "the following of a rule" I mean a literal rule such as a connective is actually used to reach a conclusion. The argument A->not-A therefore not-A ...
I may have mispoken, but to me the full meaning of "If P then Q" captures the fact that "P does not imply Q" can still be true even though not-P v Q c...
Hmm interesting, I think my position is that the formal conditional is meaningless then, insofar as it is just symbol manipulation. I have tried to fo...
I get mixed up with this, but I think the disjunction (not-P or Q) can still be true even if P does not imply Q. So the "meaning" of the disjunctive i...
You can absolutely substitute them logically, however I do not think they mean the same thing. P->Q either means just that "P->Q" or it doesn't have a...
1. Right, I mean P entails Q. The logical equivalence (not-P or Q) is an implication of the conditional, not having the same meaning as the conditiona...
1. I take a conditional to be saying: if the antecedent is true, it can't be the case (there is no circumstances such) that the consequent is false. 2...
1. The conditional means that in the event that the antecedent is true, the consequent must be true. It is one of the logical rules that must be follo...
So actually, I would say my definition of valid is different from the ordinary formal logic definition in that I am defining validity in terms of rule...
P->Q. P. Therefore, not-Q. would both flout the meaning of the conditional, and in such a way that it changes the conclusion. It's different than what...
And a relevant rule is correctly followed just in case.. if it were the case that all the premises were true and the relevant rule is followed, then t...
Relevant rules like conditionals "And" "Or" operators-- when those are used correctly the rules are followed and the argument may be considered valid....
Here are two ideas for defining validity: (1) an argument is valid when all the relevant rules are followed. Or, (2) an argument is valid when the mea...
It has been a long time since I learned some logic and I wasn't great at it, but I do know what truth tables are and I think how to use them.; I don't...
I mean take the definition of validity, and write it as an expression using symbols and logical operators; is that something that can be done? I don't...
Okay, I actually do get that the example I just gave has "an interpretation wherein all the premises are true and the conclusion is false" such that i...
Or even if just one (but not all) of the premises is false and the conclusion is false (I am having trouble thinking of an example that meets this des...
I am not clear on how A -> not-A "makes sense" if A is true. Also, TonesInDeepFreeze, an argument where all the premises are false and the conclusion ...
Okay, correct me if I'm wrong, but you are saying that ordinary natural language is "mappable" onto formal classical logic because in formal logic a s...
While you are proving what exactly is logical, you might as well prove that 2+2=4 and that there is an external world, but I don't want to hear any of...
Then I challenge you to prove that the following argument is logical: P P->Q Therefore Q. Or that this argument is logical: All men are mortal. Socrat...
Well it seems to me that all we can rely on when it comes to logic is intuition. If logic is just a formal set of rules as to how symbols may relate t...
I know Banno; I am not disagreeing with the formal validity of that argument. I don't disagree with that either. But the argument A ? ~A ? ~A clearly ...
I think you mean to say that the one implies the other through logical equivalence. That is different than saying that the expressions mean different ...
"I disagree with regards to ordinary language" I'm not quite getting it, what is the disagreement you have concerning ordinary language? You think som...
"They probably wouldn't, because the grammar of ordinary language does not follow the rules of propositional logic. In propositional logic, the follow...
Michael, the argument is simply this: If it is raining then it is not raining. Therefore, it is not raining. Who in there right mind would conclude th...
I am referring to the "it is raining" example; the conclusion in that argument appears to be a logical leap. I get that the argument is formally valid...
I may be using "equivocal" incorrectly; what I meant is that there may be two senses of the term "valid" in a logical context; one formal, the other i...
I think you are right that material implication is a problem in the example I stated; the premise appears to not be true (and to never be true). Still...
I am not entirely sure what the original post is asking. This comment does not directly answer the original post's question: It seems that, if you acc...
Okay, but I can actually see how the edited conditional could be true. For instance, if Michael is a really great citizen, then maybe he would end up ...
I am not sure what you mean by saying "If I am American then I am the President" is true in propositional logic. But I do appreciate that that conditi...
Yes, because I have a better understanding of how to define validity in a formal context. No, because in a non-formal ordinary sense, and in a natural...
and @Hanover, and @Banno, and @all participants to this thread, I was hoping this thread would be a discussion investigating deduction, implication, a...
Insofar as the things you mentioned are objectively bad for the organism, I would argue that they are morally bad, or are at least morally worse than ...
It seems to me that science may not be very good at defining an act as right or wrong. On the other hand, I think it may be quite good at saying what ...
Follow-up question: when we say "ethics isn't a science" do we mean ethics does not require any kind of scientific knowledge and can be applied throug...
Is it a problem that "not-(A and not-A)" is also a valid conclusion of the argument? According to the definition proffered by Hanover, it would seem t...
Are there any domains (I'm thinking of ethics) where you think methodological naturalism would not be instructive, or would you recommend it as a comp...
It is an interesting problem to me because according to this website -- https://www.umsu.de/trees/#(A~1~3A)~5(A~1~3A) -- the argument is apparently va...
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