The Republic begins with Thrasymachus saying that justice is merely the order of those who presently have power. There is a lot of evidence to support this view. The argument against this is an appeal to see life in a different way.

So, what is that set of evidence against what it would bring into question? — Paine

Are you asking what arguments there could be for an ideal of justice that is not grounded on power?

If so, I would ask whether there is any rational argument to support the idea that some people should be priveleged over others. I mean we already know that, in keeping with Thrasymachus' claim that justice is merely the order of those presently in power, some people are priveleged over others, so Thrasymachus has it right perhaps that justice in its actuality does commonly serve power. The question is then whether this should even be counted as justice, if there is no rational justification for treating people differently before the law.

It is an indispensable presupposition which is in play whether you recognize it or not. — Leontiskos

As I said I see it not as being a presupposition, but as a recognition of something necessary to thought and discussion. — Janus

I'm not sure you are appreciating that the things that I am saying to you are responses to the things you have said. Hence, if you are right, and the principle of non-contradiction is "a recognition of something necessary to thought and discussion," then those who have not experienced the recognition are not making use of the principle of non-contradiction. Whereas, if I am right, they are presupposing it whether they have recognized it or not.

So are you of the belief that those who have not experienced the recognition are therefore not making use of the principle of non-contradiction?

(Again, the deeper problem as I see it is that you are underestimating the depth and importance of the principle of non-contradiction, as if it were a relatively superficial linguistic tool or else a device that is consciously deployed after recognition.)

So are you of the belief that those who have not experienced the recognition are therefore not making use of the principle of non-contradiction? — Leontiskos

No, I haven't said or suggested that. I said that discussions are usually coherent and consistent, just because if they were not, they would not be sensible discussions at all. So, people who are involved in discussions don't usually contradict themselves (because if they did, they would be presenting no clear position) or speak incoherently (because if they did, they would not be saying anything).

I haven't said or suggested that the LNC is a "relatively superficial linguistic tool" either; on the contrary it is the very basis of discursive or propositional thinking. How could you believe or propose anything if you contradicted yourself? If I said to you " It is raining at some specific location and it is not raining at that location", when would there be to respond to, what to say except "you are contradicting yourself"?

No, I haven't said or suggested that. — Janus

I claimed that the law of non-contradiction is a presupposition, and you have continually counter-claimed that it is a recognition, not a presupposition. So now we have this question before us:

• If X is a recognition, can someone who has not had the recognition still have X?

I would say that the received and obvious view is: No, someone who has not had the recognition cannot still have X. You seem to be saying that the answer is 'Yes'. You seem to think that the law of non-contradiction is "a recognition of something necessary to thought and discussion," and that people who do not have this recognition are still in possession of the law of non-contradiction. Does this position seem as odd to you as it does to me?

I haven't said or suggested that the LNC is a "relatively superficial linguistic tool" either; on the contrary it is the very basis of discursive or propositional thinking. — Janus

Okay, that is good to hear.

I don't think it is so much a matter of the principle of non-contradiction being true as it is a matter of it being necessary for sensible discussion to be achieved. — Janus

Is it?

Consider that if I assert A, and you convince me of ~A, then when I join you in proclaiming ~A, am I contradicting myself?

No, of course not, you'll say. But suppose I say A at one time and ~A at another, without anyone having argued for ~A, then I'm contradicting myself? Apparently my thinking has changed, as apparently it had when you convinced me. Is that contradiction? Does being convinced magically absolve me of inconsistency?

How close together must my saying A and saying ~A be before it counts as a contradiction? How far apart must they be before you call it "changing my mind"?

Now consider the other claim made routinely around here: you say A, but A entails B and you don't want to say B so you ought to give up A. Chances are that I'll dispute the entailment or add in some condition that blocks it, or I'll say B is fine after all, or - or - or -. You try to hang a charge of being inconsistent on me and I weasel out of it somehow -- mustn't contradict myself! -- and this is what we want to hold up as the paradigm of rationality?

On the other hand it is a known fact that people do not appreciate particularly the implications of their beliefs and that inconsistency lurks on the edges of everyone's thinking. Now and then it makes conversation frustrating but it doesn't seem to make it impossible.

the depth and importance of the principle of non-contradiction — Leontiskos

people who are involved in discussions don't usually contradict themselves (because if they did, they would be presenting no clear position) or speak incoherently (because if they did, they would not be saying anything) — Janus

I'm not convinced civilization would collapse if people were inconsistent and contradicted themselves, because I think they are and they do, consistently.

But that also means I'm inclined to throw out this framing of people as consistent or inconsistent. I'm not sure you can pull off partitioning people that way. Your ultimate backstop is going to be a single compound statement of the form P & ~P, with the usual caveats. If people don't ever say things like that -- leaving aside, though I'm loath to, rhetorical usages -- that's interesting, but it's not the same as only ever asserting P and never ~P, and it's not the same as having a set of beliefs that supports only one of the two.

Count me as the skeptic there is any such law.

Obligatory quote.

The past and present wilt—I have fill'd them, emptied them.
And proceed to fill my next fold of the future.

Listener up there! what have you to confide to me?
Look in my face while I snuff the sidle of evening,
(Talk honestly, no one else hears you, and I stay only a minute longer.)

Do I contradict myself?
Very well then I contradict myself,
(I am large, I contain multitudes.) — Walt Whitman

If the LNC is something we recognize it does not follow that it is nothing but a recognition. In fact, it couldn't be: something must exist first in order to be recognized.

Consider that if I assert A, and you convince me of ~A, then when I join you in proclaiming ~A, am I contradicting myself? — Srap Tasmaner

Of course not, you would merely be changing your mind. To contradict oneself is to simultaneously claim two contradictory things. In other words if you contrdict yourself in the sense I am addressing, then you would have no position to defend.

I'm not convinced civilization would collapse if people were inconsistent and contradicted themselves, because I think they are and they do, consistently. — Srap Tasmaner

I agree and I haven't anywhere said anything about civilization collapsing: I was only addressing what is required in order to have a sensible discussion, I wasn't claiming that the world is replete with sensible discussions.

Whitman is a poet, not an rational arguer, and in any case would you say he does actually contradict himself there?

If the LNC is something we recognize it does not follow that it is nothing but a recognition. In fact, it couldn't be: something must exist first in order to be recognized. — Janus

The same question persists even if we want to talk about the PNC as the thing recognized rather than a recognition:

• If X is something we recognize, can someone who has not recognized X still possess and use it?

(Note that you are the one who first implied that the PNC as a recognition involves exclusion, namely that because it is a recognition it is therefore not a presupposition.)

To contradict oneself is to simultaneously claim two contradictory things. — Janus

Do you often say two things simultaneously?

would you say he does actually contradict himself there? — Janus

He's already gone, that's the point of the whole passage and why I posted it. Our mental lives are oriented toward the future. What does it matter if a moment ago I thought there's no way there's a tiger in those bushes? And so it goes, we continually leave thoughts behind, continually update our beliefs. Our beliefs one moment are never consistent with the last, by design and a good thing too, else how would we learn about the world.

Here's my favorite passage -- and for @Wayfarer the most beautiful description I know of the "subject of experience" -- and in this one there's a direct contradiction:

Trippers and askers surround me,
People I meet, the effect upon me of my early life or the ward and city I live in, or the nation,
The latest dates, discoveries, inventions, societies, authors old and new,
My dinner, dress, associates, looks, compliments, dues,
The real or fancied indifference of some man or woman I love,
The sickness of one of my folks or of myself or ill-doing or loss or lack of money, or depressions or exaltations,
Battles, the horrors of fratricidal war, the fever of doubtful news, the fitful events;
These come to me days and nights and go from me again,
But they are not the Me myself.

Apart from the pulling and hauling stands what I am,
Stands amused, complacent, compassionating, idle, unitary,
Looks down, is erect, or bends an arm on an impalpable certain rest,
Looking with side-curved head curious what will come next,
Both in and out of the game and watching and wondering at it.

Backward I see in my own days where I sweated through fog with linguists and contenders,
I have no mockings or arguments, I witness and wait. — Leaves of Grass 4

"Both in and out of the game and watching and wondering at it." I feel that every hour of every day. But it's a contradiction.

Forgot that last pair of lines, which are weirdly on point.

Beautiful. Co-incidentally I was listening to a youtube lecture whilst working out, which mentions a book called The Paradox of Subjectivity, apparently about this paradox.

As I said I see it not as being a presupposition, but as a recognition of something necessary to thought and discussion. — Janus

I think you are likely correct to see it as a matter of recognition. I was discussing my ideas on that with Srap here.

↪Srap Tasmaner
Whitman is a poet, not an rational arguer, and in any case would you say he does actually contradict himself there? — Janus

In case anyone’s interested, in the name of philosophical accuracy, the law of non-contradiction states that A and ~A cannot both be at the same time and in the same respect. If both A and ~A are at different times or at the same time but in different respects, then the law of non-contradiction is not broken or violated.

Whitman’s contradictions do not (or at the very least cannot be proven to be of the type that would) violate the law of non-contradiction. Just as saying “Yes and no (i.e., not yes)” or “they’re the same but different (i.e., not the same)” doesn’t violate this law, since all such non-technical contradictions implicitly affirm either that A and ~A occur at different times or that A and ~A simultaneously occur in different respects.

Apropos, the law of non-contradiction as intended by Aristotle can well be interpreted as applying to everything, and not just thoughts and propositions and percepts: at the very least, all macroscopic objective objects abide by it. (And, if we wouldn't take this for granted, I imagine we'd be direly grateful for such a world, here including our own body parts.) On the other hand, if it weren’t for this law, or universal principle, then there’d be no biggie to comprehending particle-wave duality in QM. But no one can intuit that X is both a particle and not a particle at the same time and in the same way. Hence the incomprehensibility of much of QM as its currently interpreted.

in the name of philosophical accuracy, the law of non-contradiction states that A and ~A cannot both be at the same time and in the same respect — javra

Yes, yes, we all know you can make this sound more precise, but ceteris paribus conditions always grow toward infinity. How fully do you think you can specify "in the same respect"?

Hence the incomprehensibility of much of QM as its currently interpreted. — javra

I'm not going to wade into QM interpretation -- I wear water wings even in the shallow end of that pool -- but I think you needed something here besides "QM is incomprehensible" else you're undermining your own case.

And don't forget the other major paradigm shift in modern physics. You casually invoke simultaneity in your precise definition of the LNC. Feel on solid ground there? No qualms at all about specifying some universal time-stamp for phenomena? We just recently here on the forum had a discussion of an event that will appear to have occurred in one frame of reference but not in another, and there's a paradox if those frames of reference can communicate about it.

Let's put it this way: the law of non-contradiction appears to be a rule that would be suitable for an omniscient god. Down here in mortal land, we frequently have good reasons for both P and ~P. Some of this just goes away if instead of laying down rules for the universe to follow, we just note that all of our beliefs are held with some degree of confidence, so a belief that P with a confidence of 0.90 is the same as a belief that ~P with a confidence of 0.10. Every opinion we hold is a contradiction viewed this way, which is just to say that the contradiction framing is not particularly useful.

es, yes, we all know you can make this sound more precise, — Srap Tasmaner

TMK, it’s the way the LNC has always been worded and understood since the time of Aristotle.

Anyway - as an aside that I find interesting - wanted to point out that, as per Leibniz, the law of non-contradiction can be deemed entailed by the law of identity. As one example, one can word the law of identity this way:

At any given time t, A can only be equivalent to A, this in all conceivable ways. (otherwise, A would not be equivalent to A)

And then the LNC can be worded this way: at any given time t, A cannot be ~A in all conceivable ways. (which is the same as saying: A and ~A cannot both occur at the same time (i.e., simultaneously) and in exactly the same respect).

Hence, if this holds, then to deem the law of non-contradiction inapplicable will then be to then deem the law of identity inapplicable; for, if the LNC is violated, then so too is the law of identity. ... Unless one engages in dialetheism.

BTW, a belief that A which is held with a probability of .90 is not contradicted by a belief that ~A held with a probability of .10. Each proposition entails the other, for they address the same thing. The LNC however does affirm that it is not possible to hold a belief that A with .90 probability while at the same time holding a belief that A with .10 probability.

BTW, a belief that A which is held with a probability of .90 is not contradicted by a belief that ~A held with a probability of .10. Each proposition entails the other, for they address the same thing. The LNC however does affirm that it not possible to hold a belief that A with .90 probability while at the same time holding a belief that A with .10 probability. — javra

It depends.

I thought you were going to finish that paragraph with A at 0.7 and ~A at 0.7, which should also be impossible but is known to happen, at least when considering the implications of people's beliefs. Polls routinely show slightly (and sometimes not so slightly) inconsistent opinions, and are notoriously dependent on how the questions are worded. How the questions are worded suggests a certain framework, calls up particular associations, all that extra-logical stuff. I think the approach you take suggests it would be possible to word questions "perfectly" to account for all of this and only get consistent results. I not only doubt any such thing is possible, I'm not sure it's coherent to claim that it is. There's just too much language getting in the way when you put things into words, so your first step will have to be to make the questions non-linguistic.

And then what is it the LNC actually applies to? Is it the non-verbal intellections of God?

I thought you were going to finish that paragraph with A at 0.7 and ~A at 0.7, which should also be impossible but is known to happen, at least when considering the implications of people's beliefs. — Srap Tasmaner

Sure. Its called hypocrisy or doublethink. But no one actively holds two (or more) contradictory beliefs at the same instant. Instead, one flip-flops between them while upholding both as true.

As to doubting: One can choose to doubt anything, including what is is. But doubt, of itself, does not affirm, i.e. posit, anything.

And then what is it the LNC actually applies to? Is it the non-verbal intellections of God? — Srap Tasmaner

While I don't share many another's phobias of the possibility of divinity, the basic answer is no more or no less then laws of nature, such as that of gravity. Which is to say, who the heck can conclusively answer this & by no means necessarily. It could be as much an uncreated "just is" aspect of reality as matter is to the materialist.

The LNC however does affirm that it is not possible to hold a belief that A with .90 probability while at the same time holding a belief that A with .10 probability. — javra

This looks like magical thinking about the LNC to me. Humans aren't binary logic machines.

OK. That said, it certainly doesn't look like that to me.

Which is to say, who the heck can conclusively answer this & by no means necessarily. It could be as much an uncreated "just is" aspect of reality as matter is to the materialist. — javra

Okay, but you can't possibly find that satisfactory. That is the weakest conceivable position it is possible to take and still call this 'philosophy'. I'll pass. -- But having passed, I have to wonder about a position that says "who the heck knows" and then makes a claim about the nature of reality. Doesn't inspire confidence. Are you even sure you know what you're claiming?

But no one actively holds two (or more) contradictory beliefs at the same instant. Instead, one flip-flops between them while upholding both as true. — javra

So when it comes to reasoning, what is it we're upholding again? What's the model of rationality we should aspire to? Flip-flopping and hypocrisy are fine so long as you don't contradict yourself? We're supposed not to contradict ourselves because it's a bad thing to do. (In some circles, the principle of explosion will be darkly alluded to.) But your position is that we don't just because we can't, and we do the next best thing, which is advocating contradictory positions seconds apart. If we want to say that's not okay either, evidently the "law" of non-contradiction won't be any help, and we'll need a whole 'nother principle to rule that out.

Are you even sure you know what you're claiming? — Srap Tasmaner

We don't seem to share the same wants when it comes to philosophy. I'm interested to ground my beliefs on what is. If I can't currently fully explain all that is, that's OK by me - so long as my beliefs regarding what is are sound. I dislike forsaking truths because they don't fit in with the explanatory model I so far have. What I'm claiming, in short, is that the LNC appears to be sound. The possible implications of this take a very distant second place for me.

What's the model of rationality we should aspire to? Flip-flopping and hypocrisy are fine so long as you don't contradict yourself? We're supposed not to contradict ourselves because it's a bad thing to do. — Srap Tasmaner

This is entirely an issue of ethics (and value-theory): what ought we do. As I think you're by now very aware of, arguments are sometimes engaged in with the outlook of "winning at all costs" - such that snide remarks and innuendos intended to humiliate the "opponent" are given in arguments by those who uphold the just mentioned ought. Whether this is rational or not fully depends on the goal one has in mind: e.g., to win and subjugate at all costs or, as corny as this might sound, to better discover truths and only then their likely relations. If one intends the former, then its rational to belittle and dehumanize the other. If one intends the latter, then it is not. But, again, this is an issue of what one ought do and, hence, one of ethics.

p.s. the same then goes for whether contradicting ourselves in rational discourse is good or bad: it depends on one's overall goal in so engaging in discourse.

We don't seem to share the same wants when it comes to philosophy. — javra

Indeed. I think reasoning serves a purpose.

Probably nothing more to be gained from further discussion, but it was fun. Appreciate you indulging my heterodoxy.

:up:

Indeed. I think reasoning serves a purpose. — Srap Tasmaner

I should add: so do I (multiple possible purposes). But we will likely disagree on the details. It was good debating with you.

Do you often say two things simultaneously? — Srap Tasmaner

Obviously two things cannot be said strictly simultaneously. What I meant was that within the presentation of an argument self-contradiction would make it unclear what position was being asserted, or even mean that no position is being asserted.

So this kind of thing

Our beliefs one moment are never consistent with the last, by design and a good thing too, else how would we learn about the world. — Srap Tasmaner

I agree with and has really nothing to do with what I've been arguing. I would never deny that we can learn something new and/ or change our minds.

I agree with what you say except for this

On the other hand, if it weren’t for this law, or universal principle, then there’d be no biggie to comprehending particle-wave duality in QM. But no one can intuit that X is both a particle and not a particle at the same time and in the same way. Hence the incomprehensibility of much of QM as its currently interpreted. — javra

To say that something could be simultaneously wave and particle does not constitute a logical contradiction as far as I can tell. We might think there is an incompatibility between the two states, but maybe our understanding or imagination is just not up to the task, If it is a fact that something can be both wave and particle, then it is a fact, pure and simple.

I think you are likely correct to see it as a matter of recognition. I was discussing my ideas on that with Srap here. — wonderer1

:cool:

To say that something could be simultaneously wave and particle does not constitute a logical contradiction as far as I can tell. We might think there is an incompatibility between the two states, but maybe our understanding or imagination is just not up to the task, If it is a fact that something can be both wave and particle, then it is a fact, pure and simple. — Janus

This, I think, will depend on what significance one imports into the terms "particle" and "wave". If the LNC does hold, however, then one can not have a photon be both a particle (A) and not a particle (~A) at the same time and in the same respect.

For example, it might be that the unobserved photon is neither spatially localized (particle) nor disperse fluctuations (wave) but something else that can account for both observations.

That said, as to our imagination likely not being up to par, as I tried to previously express, I agree.

What I meant was that within the presentation of an argument self-contradiction would make it unclear what position was being asserted, or even mean that no position is being asserted. — Janus

I just don't see how you're going to cleanly partition what is and what isn't part of an argument.

Why am I even arguing about this?

I don't think the LNC is useful at all as a description of how people reason or how they argue. People are frequently inconsistent, and philosophers know that better than most, not least because they accuse each other of it all the time. I see no sign that communication requires the kind of perfect consistency suggested, and I suspect there's a terribly unrealistic model of language and communication at work there.

I doubt the LNC is even useful as an ideal to strive for. If our mental faculties are primarily geared toward making useful predictions, and those predictions are probabilistic, I don't see what the LNC even brings to the table. My beliefs are mixed, my expectations are mixed, the evidence I accumulate is mixed, and what's required of me is flexibility, continual updating and exploration. It's not a matter of adding or subtracting atomic beliefs from my store of truths; change is always cascading through the system of my beliefs, modifying the meaning even of beliefs I "retain".

I do think I get where you're coming from, as a reformed logic guy myself. I'm not really arguing to convince you, just giving you some idea why I don't find much of value or interest in the LNC.

People are frequently inconsistent, and philosophers know that better than most, not least because they accuse each other of it all the time. — Srap Tasmaner

That's probably true, but if inconsistencies in your position, which you were unaware of, are pointed out to you, would it not be intellectually dishonest to refuse to acknowledge that? And if your position is self-contradictory would that not amount to being no position at all?

BTW, I'm not advocating that people should take up a position; I actually prefer to avoid holding views about anything at all as much as possible.

I doubt the LNC is even useful as an ideal to strive for. If our mental faculties are primarily geared toward making useful predictions, and those predictions are probabilistic, I don't see what the LNC even brings to the table. — Srap Tasmaner

I can relate to that, but what if you added "I don't doubt the LNC is useful as an ideal to strive for. I think our mental faculties are not primarily geared towards making useful predictions, and that those predictions are not probabilistic, so I can see the usefulness of the LNC.

You would then be contradicting yourself, and in that case how would I know what you were arguing for?

This, I think, will depend on what significance one imports into the terms "particle" and "wave". If the LNC does hold, however, then one can not have a photon be both a particle (A) and not a particle (~A) at the same time and in the same respect.

For example, it might be that the unobserved photon is neither spatially localized (particle) nor disperse fluctuations (wave) but something else that can account for both observations.

That said, as to our imagination likely not being up to par, as I tried to previously express, I agree. — javra

I will just point out that a photon being a wave and a particle is not logically equivalent to a photon both being and not being a particle, because it being a wave does not logically rule out its also being a particle.

but what if you added — Janus

Well, that's the thing. It's really already in there, because we're just talking about a working hypothesis, just pragmatism. All bets come hedged.

And if your position is self-contradictory would that not amount to being no position at all? — Janus

I don't know what to say to that because I don't see how it's a useful question. It's fighting the last war.

Should I be afraid that I might sometimes sound like I have an opinion when, unbeknownst to me, I don't?

Should I worry that I might try to predict whether that rock will hit me but somehow fail to make any prediction at all because a contradiction snuck in somewhere?

Reasoning as we actually do it is a rough and ready business, constantly on the move. I can imagine arguing that contradictions get weeded out because they're inherently useless, being necessarily false, but I doubt even that's right. We often have good reason to believe both sides of a story, so we keep our options open, and for a while they live side by side. So what?