I could if you prefer. Doesn’t really make a difference I suppose.

There is a subtle difference in some systems of logics between a statement, that is "just made" and a statement which is "proveably true".

I’m not really sure what you’re getting at. I’m just explaining what the technical terms “valid” and “sound” mean within the domain of deductive reasoning.

https://en.m.wikipedia.org/wiki/Validity_(logic)

In logic, specifically in deductive reasoning, an argument is valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false. It is not required for a valid argument to have premises that are actually true, but to have premises that, if they were true, would guarantee the truth of the argument's conclusion.

https://en.m.wikipedia.org/wiki/Soundness

In logic, more precisely in deductive reasoning, an argument is sound if it is both valid in form and its premises are true.

In logic, more precisely in deductive reasoning, an argument is sound if it is both valid in form and its premises are true.

Yes - read the linked document. That is, what we are talking about.

If for example, the grass is wet, it has to have become wet somehow. If we were in a world where this can only happen by rain, the conclusion clearly is that it must have rained. — Heiko

And this is the type of tension that I think the realist has - that logic is supposed to give warrant for the belief in rTruth, but the world doesn't function deductively (from generalizations to specifics), rather it just is. Probabilistic, stochastic, etc. logics which can account for the variance between premises and conclusions are deemed insufficient to give warrant (let alone certainty) for the realist, but logic can never demonstrate other than which what was assumed. So if we demand binary truth values (for unitary propositions or compound propositions), but our best methods for predicting/accounting for the world are not perfectly accurate, what is the role of such logics for the realist? It cannot do what it sets out to do (make an rTruth) and its predictive and truth preservation properties are inherently disconnected from the way that rTruths appear to relate to themselves, so what is the allure?

I am looking for an argument of what logic does for the realist besides act as a useful heuristic. In particular, I am looking for an argument as to why anyone should feel compelled to accept classical logical (or minor variations) as somehow more useful as a heuristic than any other logic.

I’m lost now. Are you objecting to something I’m saying?

I am looking for an argument of what logic does for the realist besides act as a useful heuristic. — Ennui Elucidator

It provides a guarantee of understandability for other beings. I guess you could get an agreement of any realist when showing the fundamental set operations - e.g. "O O is disjoint" and he will agree that no point in one O is also in the other. It is not so much the content but the basic rules of logic themselves that have a certain type of "reality".

Other than that - I do not understand your concept of rTruth completely: E.g. If you feel a poke in the back, is there "really" something that pokes you? I guess the answer is "no": it is a conclusion that everything has cause. I am not sure that all realists would reduce reality to just the given content of consciousness. In another thread I pointed out that (following e.g. Heidegger) reality seems to be purely negative - that it is mainly what _prevents_ you to assume somehing. In logics this would be a statement not(x) where x is the "state of affairs as assumed".

Other than that - I do not understand your concept of rTruth completely: E.g. If you feel a poke in the back, is there "really" something that pokes you? I guess the answer is "no": it is a conclusion that everything has cause. I am not sure that all realists would reduce reality to just the given content of consciousness. In another thread I pointed out that (following e.g. Heidegger) reality seems to be purely negative - that it is mainly what _prevents_ you to assume something. In logics this would be a statement not(x) where x is the "state of affairs as assumed". — Heiko

Realism, as being used here, is about people who think that what makes a proposition true is its relation to the states of affairs. I am not a realist. I am, however, interested in non-binary, relevant, paraconistent, etc. logics and how they solve real world problems that classical logic (however slightly modified) cannot (or perhaps they solve such problems more efficiently). I see logic more as a tool of thinking than a thing capable of governing the world (i.e. logical necessity/entailment/possibility does not preclude otherwise efficacious behavior).

I am, however, interested in non-binary, relevant, paraconistent, etc. logics and how they solve real world problems that classical logic (however slightly modified) cannot (or perhaps they solve such problems more efficiently). — Ennui Elucidator

Okay, nice to meet you :)
In fact, every now and then I have to deal with such "problems".
( Warning: possibly boring stuff ahead )
When evaluating a logical system of facts and rules there are (at least) 2 possible ground-laying assumptions.
"closed world": which means the system is complete in that "it is known, that _all_ true statements can be derived from it" and
"open world" which means that "some things are known, some are not".

When dealing with an open world there is a problem with "tertium non datur" (a or not a) - it might well be that not enough facts are known to prove or disprove "a". Classical logic assumes that "a" or "not a" MUST be true. This is a reality of logics itself but does paradoxically not hold if talking about e.g. mathematical systems (Goedel's incompleteness theorem).
Now the discussion must be lifted one step higher and we arrive at the question what it means (in logics) to say, for example, "a is the case". There are some alternative mathematical logics which account for the (un-)provability problem by eliminating the tertium-non-datur and the law of the double-negation by saying "x" means that "a proof can be contructed for x" and "not(x)" means "a proof can be constructed for not(x)". Doing this a failure to construct a proof for "not(x)" no longer necessarily implies "x", which makes the logic weaker (and suitable for an open world).

I get the intention of your distinction between l- and r-truth, but the world does not speak. In logics one is dealing with rigidly defined concepts. A "matter of formulation" can make the difference between true or false. I am not sure if humans act logically without a reflection in "words".

I’m not sure what you mean by “seems to evaluate” in this case. My hope was that by using a mathematical truth as the antecedent, that we could highlight that any true premises plus valid form makes “P” true of logical necessity. Logic is, perhaps, about establishing (discovering?) the rules by which the truth value of one proposition relates to the truth value of another. Classical logic, where any proposition can stand in for any other proposition with the same truth value, leads to many intuitively unsatisfactory “proofs”. — Ennui Elucidator

Then I'm not at all sure what your task is in this thread.

But then, logic is simply playing with symbols, isn't it? What more was expected?

Thanks for the mention of antirealism, but truth-bearers confuse me even more. I can't see how they help.

I am looking for an argument as to why anyone should feel compelled to accept classical logical (or minor variations) as somehow more useful as a heuristic than any other logic. — Ennui Elucidator

My inclination is to say simply that we can choose whatever logic suits our purpose. DO you thin this somehow incompatible with realism?

My inclination is to say simply that we can choose whatever logic suits our purpose. DO you thin this somehow incompatible with realism? — Banno

Trump and Trumpistas are realists then?

In particular, I am looking for an argument as to why anyone should feel compelled to accept classical logical (or minor variations) as somehow more useful as a heuristic than any other logic. — Ennui Elucidator

Indeed, why not make Eristische Dialektik our Bible?

My inclination is to say simply that we can choose whatever logic suits our purpose. DO you thin this somehow incompatible with realism? — Banno

I am suggesting quite the opposite - that if truthmakers are states of affairs, then logic should not be faulted for its failure to ensure rTruth. In other words, realists should feel free to use whatever logic they want including the acceptance or denial of any particular rule no matter how much of a sacred cow it is. If a logic occasionally produces an useful result, we just use a different one. If our concern is about preserving lTruth, then we apply a different criteria to our logic than if our concern is predicting the behavior of light through a slit as it spins our radiometer.

Universal logic which is responsible both for rTruth and lTruth feels much like ancient baggage. Thinking can be dynamic and free and so long as our methods achieve our ends, what more can we ask of them? If you want realism, it doesn’t require the baggage of a particular logic.

Indeed, why not makeEristische Dialektik our Bible? — baker

Well I don’t understand the Bible in Latin or German, why should another German book that I don’t understand fail to qualify as a bible? The title sounds grand though.

Banno may tell you that he never laughs at my jokes.

Persuade the Audience, Not The Opponent
This is chiefly practicable in a dispute between scholars in the presence of the unlearned. If you have no argument ad rem, and none either ad hominem, you can make one ad auditores; that is to say, you can start some invalid objection, which, however, only an expert sees to be invalid. Now your opponent is an expert, but those who form your audience are not, and accordingly in their eyes he is defeated; particularly if the objection which you make places him in any ridiculous light. People are ready to laugh, and you have the laughers on your side. To show that your objection is an idle one, would require a long explanation on the part of your opponent, and a reference to the principles of the branch of knowledge in question, or to the elements of the matter which you are discussing; and people are not disposed to listen to it. For example, your opponent states that in the original formation of a mountain-range the granite and other elements in its composition were, by reason of their high temperature, in a fluid or molten state; that the temperature must have amounted to some 480 degrees Fahrenheit; and that when the mass took shape it was covered by the sea. You reply, by an argument ad auditores, that at that temperature - nay, indeed, long before it had been reached, namely, at 212 degrees Fahrenheit - the sea would have been boiled away, and spread through the air in the form of steam. At this the audience laughs. To refute the objection, your opponent would have to show that the boiling-point depends not only on the degree of warmth, but also on the atmospheric pressure; and that as soon as about half the sea-water had gone off in the shape of steam, this pressure would be so greatly increased that the rest of it would fail to boil even at a temperature of 480 degrees. He is debarred from giving this explanation, as it would require a treatise to demonstrate the matter to those who had no acquaintance with physics. — “The Art of Being Right”

There are some alternative mathematical logics which account for the (un-)provability problem by eliminating the tertium-non-datur and the law of the double-negation by saying "x" means that "a proof can be contructed for x" and "not(x)" means "a proof can be constructed for not(x)". Doing this a failure to construct a proof for "not(x)" no longer necessarily implies "x", which makes the logic weaker (and suitable for an open world). — Heiko

So this is a type of motivation of mine - to understand that where we have warrant for both X and ~X, that we shouldn’t somehow dismiss the warrant of one or the other for fear of contradiction. Although not fully explicated here, the thought is that the way that we speak of truth is neither about coherence nor correspondence, but about achieving our ends. We can grant the realist his state of affairs for rTruth, move into why rTruth is utterly meaningless for epistemology, and then get on with the business of thinking well about solving our problems. It would be nice, however, if the realist would cease their reproach of logics that don’t meet their aesthetic based upon the faulty belief that logic is about the state of affairs.

I am suggesting quite the opposite - that if truthmakers are states of affairs, then logic should not be faulted for its failure to ensure rTruth. — Ennui Elucidator

It seems that for all practical intents and purposes, (formal) logic is a response or reaction to what is intuitively felt as wrong thinking. In other words, for many practical intents and purposes, the history of logic is the history of addressing informal logical fallacies (and then explicating principles of proper ways of thinking).

The issue is relevant when it comes to persuasion, when one person tries to persuade another person to accept the proposed view and act accordingly.

Ideally, fending against informal logical fallacies should protect one against being duped (and, if one is very nice, make one refrain from duping others).

Although not fully explicated here, the thought is that the way that speak of truth is neither about coherence nor correspondence, but about achieving our ends. — Ennui Elucidator

Agreed.

It would be nice, however, if the realist would cease their reproach of logics that don’t meet their aesthetic based upon the faulty belief that logic is about the state of affairs.

Unless this belief (or, to the point: asserting this belief) is part of the realist's strategy to achieve his ends.

It's not like it is really possible to distinguish between a religious preacher who claims to have the Truth, the How Things really Are, the State of Affairs, from a realist who does the same (they just differ in what they state that Truth to be).

Ideally, fending against informal logical fallacies should protect one against being duped (and, if one is very nice, make one refrain from duping others). — baker

I want very much to like this, but there are times when informal fallacies are useful - like appeals to authority or ad hominem when it is so much more trouble to show why the person is wrong. If an informal fallacy gets you to the same end with more expedience, I question why they shouldn’t be given the same status as any other heuristic.

I want very much to like this, but there are times when informal fallacies are useful - like appeals to authority or ad hominem when it is so much more trouble to show why the person is wrong. If an informal fallacy gets you to the same end with more expedience, I question why they shouldn’t be given the same status as any other heuristic. — Ennui Elucidator

Indeed.

From your link:

For example, I may advance a proof of some assertion, and my adversary may refute the proof, and thus appear to have refuted the assertion, for which there may, nevertheless, be other proofs. In this case, of course, my adversary and I change places: he comes off best, although, as a matter of fact, he is in the wrong.

If the reader asks how this is, I reply that it is simply the natural baseness of human nature. If human nature were not base, but thoroughly honourable, we should in every debate have no other aim than the discovery of truth; we should not in the least care whether the truth proved to be in favour of the opinion which we had begun by expressing, or of the opinion of our adversary. That we should regard as a matter of no moment, or, at any rate, of very secondary consequence; but, as things are, it is the main concern. Our innate vanity, which is particularly sensitive in reference to our intellectual powers, will not suffer us to allow that our first position was wrong and our adversary's right. The way out of this difficulty would be simply to take the trouble always to form a correct judgment. For this a man would have to think before he spoke. But, with most men, innate vanity is accompanied by loquacity and innate
dishonesty. They speak before they think; and even though they may afterwards perceive that they are wrong, and that what they assert is false, they want it to seem the contrary. The interest in truth, which may be presumed to have been their only motive when they stated the proposition alleged to be true, now gives way to the interests of vanity: and so, for the sake of vanity, what is true must seem false, and what is false must seem true.

The question is whether we should fully give in to the natural baseness of human nature, whether we should deem it absolute, the only thing that matters.

I fear the systems I was talking about are those, where there is neither a sufficient reason for X nor ~X.
_Paraconsistency_ (allowing contradiction) is seldomly seen as allowable for a single subject, but (accoring to wikipedia) a model for what can be derived from the statements of _multiple_ speakers, i.e. a social context. There is no contradiction in two people disagreeing, but the contradiction exists in the social context.

Regarding tertium-non-datur and rTruth:
Imagine the sentence "At point X on the ground of a deep ocean there are the ruins of Atlantis". Nobody has ever been at the given point X. What can we say about the truth value of that sentence apart from "might be"? Tertium-non-datur means ideally "we can get there, have a look and then _know_ if this is true". It has to be true or not when we know everything. But this is not the state-of-affairs. We do _not_ know this. That is, tertium-non-datur, realistically only applies where the truth of one of the negations is already known. "The sun is shining, therefor 'The sun is shining or not' is true".
Is "It is not raining" rtrue on a sunny day? I do not know.

I would not go so far as to say, we choose the logic that serves our ends (as in egoism etc.). But we have to choose the right logic for modeling different realities. The fitting logic is still determined by the nature of things - which leads back to the epistemological starting point and social contradictions.

I am suggesting quite the opposite — Ennui Elucidator

Your "quite the opposite" is the same as I sugested, so it seems you are a man of your word.

DO you thin this somehow incompatible with realism? — Banno

I was responding to this question. Perhaps I misunderstood the tone.