You are unbelievable. I, again, repeat: What makes them (let's speak plain english) "correct thinking"? You haven't answered that, you simply said they are not accidentally so, but essentially so. No argument is given, you're just saying they are. — MindForged
"Foundational reflection" will necessarily presuppose other principles. — MindForged
ex contradictione sequitur quodlibet — Dfpolis
There's no reason to think the rules you presuppose in entering such reflection are inherently correct. — MindForged
The problem is such an examination will require reasoning. — MindForged
And correct reasoning (or form of thought, correct thinking, whatever) already presupposes a set of correct logical rules you are abiding by. — MindForged
You don't get around this by recourse to "reality" (an already contentious concept; people consider many different things part of reality). — MindForged
I gave an explosive argument in Aristotelian terms but which is not valid because contradictions do not imply anything in traditional logic. — MindForged
Assume two contradictory premises: A.) 'All ice cream is frozen.'; B.) 'Not all ice cream is frozen.'
Now, just to show that it's possible, say one wants to use those two premises to prove that: C.) 'Words don't exist'.
To do so, construct a disjunction out of A and C:
'All ice cream is frozen or words don't exist.'
This statement appears to be perfectly acceptable here because it holds true under any of these three circumstances:
1. All ice cream is frozen.
2. Words don't exist.
3. All ice cream is frozen and words don't exist.
(Of which at least the first one is true because it was assumed as a premise.)
Now use that disjunction for a disjunctive syllogism:
'All ice cream is frozen or words don't exist.
Not all ice cream is frozen.
Therefore words don't exist.'
This also appears to be perfectly acceptable here because if it is said that at least one of A or C are true, then when it turns out A is not true (which is B, which has been accepted as a premise), at least it can be held that C is true.
I didn't say Frege created the principle of explosion, I said it was not what you might call logical orthodoxy until Frege made it part of Classical Logic. — MindForged
The works of medieval logicians cannot in any way be said to have been the standard logic, ever. By Kant's time they had been lost to history and not even remembered. — MindForged
"Two case" as in two cases of observation, not two cases of different objects. Schrodinger goes to pains to make clear that the object is not self-identical despite the reasonable assumption of there being a causal connection between what one observes. — MindForged
Identity entails that objects are individuated. If some object (or set of objects) lacks individuation conditions, then they are not self-identical. — MindForged
I did not say the rule was different, I said the rules were different. I went on to say that, according to Aristotle (as per your quote), Excluded Middle does not apply to future contingents. — MindForged
In the case of future contingents, we can still reason about them. Aristotle does not say Non-contradiction no longer applies, nor does he say that Identity fails to apply. But that Excluded Middle no longer does. — MindForged
When the subject, however, is individual, and that which is predicated of it relates to the future, the case is altered. For if all propositions whether positive or negative are either true or false, then any given predicate must either belong to the subject or not, so that if one man affirms that an event of a given character will take place and another denies it, it is plain that the statement of the one will correspond with reality and that of the other will not. — Aristotle, De Interpretatione, 9
in some instances there are real alternatives, in which case the affirmation is no more true and no more false than the denial — Aristotle, De Interpretatione, 9
A sea-fight must either take place to-morrow or not, but it is not necessary that it should take place to-morrow, neither is it necessary that it should not take place, yet it is necessary that it either should or should not take place to-morrow. — Aristotle, De Interpretatione, 9
This is the case with regard to that which is not always existent or not always nonexistent. One of the two propositions in such instances must be true and the other false, but we cannot say determinately that this or that is false, but must leave the alternative undecided. One may indeed be more likely to be true than the other, but it cannot be either actually true or actually false. It is therefore plain that it is not necessary that of an affirmation and a denial one should be true and the other false. For in the case of that which exists potentially, but not actually, the rule which applies to that which exists actually does not hold good. The case is rather as we have indicated. — Aristotle, De Interpretatione, 9
It's a view that liar-type sentences are not well-formed, not that truth-values are not well-formed. — MindForged
Note that "Everything Jones says about Watergate is true." is not a statement about the reality of Watergate, but one about Jones' statements. Similarly, "Most of Nixon's assertions about Watergate are false," is not a statement about Watergate, but about Nixon's locutions. Thus, it cannot be counted among "Nixon's assertions about Watergate."
Statements that people make are real. Statements made about other statements are common, — MindForged
I've no idea how you came to that conclusion. If Jones only says Nixon is mostly lying about Watergate, and Nixon says everything Jones says about Watergate is true, then the issue is these cannot be jointly true and yet they *entail* each other. — MindForged
You went beyond that, you said your understanding was sufficient to claim (as you did) that the principles are true essentially, rather than accidentally. — MindForged
My point is your experience doesn't generate anywhere near the justification for that. Experience is fine for generation provisional assumptions that go into your logic, but that's not what you've argued for. — MindForged
You think there is one correct way of thinking and that traditional logic corresponds to that thinking (correct me if I'm mistaken). — MindForged
With the lack of conditionals in traditional logic I'm not even sure this is consistent with the logic being proposed. — MindForged
An imagined world is by definition non-existent so how are you reasoning correctly about it? After all, the principles which apply to existing things is not supposed to apply to that which has no being. — MindForged
What I was saying was that if we take your view that truth-values are an "incoherent concept" (as you said), then modern maths/logic are not usable because they make crucial use of this and other concepts (conditionals), and dispenses with aspects of traditional logic (existential import is not assumed in quantifiers). — MindForged
And I don't see how traditional logic has done anything to further knowledge in these areas — MindForged
In the traditional case, it only meets this criterion if we only talk about what we know to be true about reality, so it's application to hypothetical and mathematical cases becomes less useful — MindForged
I already pointed out examples of what I was talking about (e.g. uniform continuity vs continuity of a function). — MindForged
Traditional logic had no theory for the quantifiers it used, the quantifiers weren't detachable, and that's in part why its application to mathematics was so limited and thus Frege had to develop a new logic. Prior, until the medieval logicians there was no real understanding of them, and even the medieval logicians treated quantifiers sort of like names. Frege made them clearer by making them a new kind of linguistic object. — MindForged
Somehow, for the 3rd or 4th time, you have skipped over the core of the answer: Thinking about reality is correct when it preserves the truth of what we know of reality (is salve veritate) -- and preserves that truth, not accidentally, but in virtue of the processed followed (i.e. essentially). This is an operational, goal-oriented definition.
It is amazing that, while noting that I said, "essentially, not accidentally," you seem unable to grasp what essential note is required. Just so you do not miss it again the essential note is truth preserving (salve veritate),
I am not discussing any "them" such as rules, but the definition of correct thinking. — Dfpolis
just sounds like a wordy way of saying that the correct way of thinking is the way of thinking that is correct ("preserves the truth of what we know of reality," etc.) Not terribly illuminating. — SophistiCat
It's not clear in this story what sort of question is being asked, and what sort of justification is being provided.1. It claims that to question logic is, itself, to be logical and therefore all criticisms of logic already subsume the principles of logic - we are looking for reasons to justify our doubts about logical authority.
2. Others claim that to justify logic is to, again, assume logic's authority. This, they allege, is a circularity and therefore logic has no justification.
So, it appears that we can neither justify nor critique logic. Both are circular. — TheMadFool
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