The Laws of Logic

[cholland]

The 'Laws of Thought' are a conceptual tool made by man. .. they have no actual reality outside of the mind of man.

Are the Laws of Logic man-made?

[Furrowed Brow]

Nope, we are talking about the 3 axioms of classical logic, and not some offsprings, which may or may not be fundamentally different.

Well intuitionistic logic for example does not have an excluded middle. Which is a right? A logic that obeys the rule of excluded middle or one that does not?

What is the right logic, a bivalent logic where something is true or false, or a fuzzy logic where something, might be partly true and the valid conclusion is blurry.

Irrelevant. We are NOT talking about the proper usage of these axioms, we are talking about the question: "are these really the only valid set of axioms"?

The question of what counts as proper usage and what counts as valid are the same question. I can name logics in which excluded middle is not valid, and can invent some in which identity and non contradiction are no valid.

Heres a logic to think about. In this logic A => A is a valid operation, but cannot be repeated, so that A <=> A does not count as valid. In this logic the act of observation gives one clear result but the act of observation interferes with that what is observed. So the second time you look to see if A implies what is was a moment ago, things are always found to have changed. In that world the classic law of identity does not hold true. Identity becomes impermanent. Kind of looks like a recipe for a temporal logic.

The question is then what makes classic logic the proper logic.

Again, you are mistaken. In your hypothesized world Thursday is not the 5th day of the week... so what is it? It cannot be answered, because there is no law of identity.

Yes. A logic without identity is very limited but it is not invalid, and depending on the kind of reality to be negotiated it may be the correct one.

If sometimes A=A but some other times A=B and yet other times A=C... then you cannot have a concept of what A happens to be.

It such a world the equivalence sign = stops making sense this kind of logic does not have that logical connective.

Nothing is what it "seems to be"?

Yes. This would be the result it seems.

That is a logically incoherent (and thus logically self-contradictory) state of affairs.

It is very limiting for sure. Everything is treated as a malleable surface. I was thinking of the character Chauncy Gardener played by Peter Sellers in the Movie Being There. This character has no insight and just kind of copies and repeats and reacts to what he sees around him. He says stuff like I see what you mean but he does not see as you or I might see things. However there is nothing invalid about negotiating life in that very simplistic way. If someone turned into a Fish whilst talking to them Chauncy Gardener might carry on the conversation without a twitch. If they stated flapping around in front of him gasping for air he might nod wisely and say I see what you mean.

In world where the state of affairs of "A=A" does not exist, where nothing has identity, there can be no beings, who are able to conceptualize anything, since they are not "themselves".

Strictly speaking there will be no distinct individual beings that conceptualise themselves, this does not mean there is no being. Maybe Nirvana lacks the law of identity.

Maybe for a second they are humans, but then in the next one they magically (like in a dream) transform into a fish, and then they become a grain of sand... Just like in a dream (random firings of the neurons) there is "nothing", if such a world you proposed would be reality (and the dream is not a reality, no matter how life-like it seems to be) there would be "nothing" there that could be grasped... where would be no one there who could do the "grasping".

It depends what is meant by grasping. Sure there would be no one who thinks like a being limited to classic logic. But other than the law of identity I am not aware of any other law that says identity must be grasped. It begs the question to ring fence identity as some special rule that underpins all logically thinking and then say all other logics are thus incoherent. Sure it underpins a class of logics whose validity holds for certain kinds of worlds and certain kinds of grasping. If you are a being that lives in a world that has mastered the law of identity then it is likely a dreamworld would seem deeply frustrating and weird. But that does not make a weird world logically invalid. It makes it weird and incoherent as view from a world in which identity holds true. We may quickly lose patience with such a world, but that does not mean there is only one way. As goat points out the laws of logic are descriptive of how we think.

[Mithrae]

In world where the state of affairs of "A=A" does not exist, where nothing has identity, there can be no beings, who are able to conceptualize anything, since they are not "themselves".

Strictly speaking there will be no distinct individual beings that conceptualise themselves, this does not mean there is no being. Maybe Nirvana lacks the law of identity.

Maybe for a second they are humans, but then in the next one they magically (like in a dream) transform into a fish, and then they become a grain of sand... Just like in a dream (random firings of the neurons) there is "nothing", if such a world you proposed would be reality (and the dream is not a reality, no matter how life-like it seems to be) there would be "nothing" there that could be grasped... where would be no one there who could do the "grasping".

It depends what is meant by grasping. Sure there would be no one who thinks like a being limited to classic logic. But other than the law of identity I am not aware of any other law that says identity must be grasped. It begs the question to ring fence identity as some special rule that underpins all logically thinking and then say all other logics are thus incoherent. Sure it underpins a class of logics whose validity holds for certain kinds of worlds and certain kinds of grasping. If you are a being that lives in a world that has mastered the law of identity then it is likely a dreamworld would seem deeply frustrating and weird. But that does not make a weird world logically invalid. It makes it weird and incoherent as view from a world in which identity holds true. We may quickly lose patience with such a world, but that does not mean there is only one way. As goat points out the laws of logic are descriptive of how we think.

Unless we're messing with time also, in this dream-world it would be the case that A was A - and it always will have been the case that A was A.

It's an interesting example, because it's an extreme illustration of the problem of identity and change. If we were to say that the law of identity was invalidated in that dream-world, in what manner and to what extent can we say that it's valid in this world simply because the changes are less drastic?

Welcome to the forum by the way, He-zen

[Furrowed Brow]

It's an interesting example, because it's an extreme illustration of the problem of identity and change. If we were to say that the law of identity was invalidated in that dream-world, in what manner and to what extent can we say that it's valid in this world simply because the changes are less drastic?

I think the answer is that we impose rules like this one to maintain order. The ship of Thebes is an interesting point in question. The ship of Thebes set sail on its long journey. It travels for years making its way from port to port effecting repairs along the way. Rope, sails, nails , planks of wood are replaced one by one until not a single original item that first set sail remains. Even the original crew and Captain have died along the way and have been replaced. The ship of Thebes eventually returns to Thebes. Is it the same ship? Does the ship of Thebes equal the ship of Thebes. I think the answer is that time, and mereological problems posed by reality mean talk of identity always requires a degree of abstraction, in the extreme examples like the ship of Thebes the law just breaks down and we dont know what to think. We might want to say that the new ship with the replaced ropes, wood, sails, nails and crew was the same ship, or we might not. If we don't wantto say it is the same ship how much of the original ship must remain for us to say that? 51%? Or if we do think it is the same ship, what if the ship with all those new ropes, wood, nails, crew came into Thebes port and docked alongside the original just before it set out on its journey. Mostly we do not face such problems in our everyday lives and so the principle is not really tested to destruction. But I think folk who watch their loved ones disintegrate from dementia, or suffer any other profound changes, face the question of identity and I guess each answers it their own way.

Watched a movie recently starring Paul Giammetti " Barneys Version. Lovely movie I thought. Anyhow he plays a character who towards the end of the movie develops dementia. There is a scene where his is with his ex wife who he continues to love very much but he does not know they are divorced and she is remarried. This Barney would never cheat on her. He thinks their grown up kids are in school, and is at that moment blissfully happy. So in Barneys version of reality he is very happily married to a women he very much loves. Is Barney a happily married man at that moment or a divorcee who cheated on his wife? Looks to me both are true depending on how the problem is framed.

[He-zen]

Sorry about the delay.

The ship of Thebes would bring us to a Clintonesque question: "what is: 'IS'?". What is "A"? If one takes the ship analogy, it creates a serious problem. Obviously, every time we take a breath, we expel some CO2 molecules and incorporate some oxygen molecules into our body.... Are we still the same? Or did we cease to exist and a brand new entity replaced "us"? When we get a haircut, or clip our nails... do we change into something totally new entity? Surely not.

[Furrowed Brow]

Sorry about the delay.

The ship of Thebes would bring us to a Clintonesque question: "what is: 'IS'?". What is "A"? If one takes the ship analogy, it creates a serious problem. Obviously, every time we take a breath, we expel some CO2 molecules and incorporate some oxygen molecules into our body.... Are we still the same? Or did we cease to exist and a brand new entity replaced "us"? When we get a haircut, or clip our nails... do we change into something totally new entity? Surely not.

This stuff can send you crazy.

How about a Parfit like Star Trek transporter thought experiment. You step into the transporter which first scans you and then rips your molecules assunder. Two interwined signals are transmitted to Mars. One is an the plasma energy made from all the atoms that were you on Earth and other is the information signal with the blueprint for reconstructing you. On Mars an exact molecular double is constructed. This You has all the same memories, and feelings, habits and itches and personality as you. It believes it is You, as far they are concerned they just stepped in a booth on Earth and then walk out the booth on Mars. Is that you?

I always so no.

[He-zen]

This stuff can send you crazy.

Sure looks complicated and intriguing.

Stanislaw Lem has described the same thought experiment in "Summa Technologiae" (the title is intentional). He created two variants of the process.

In the first one he describes a "crude" variant, where the machine reads all the pertinent information, but the reading process is destructive. All the information is transmitted to another place. The necessary atoms are collected, and arranged into the same pattern as they originally used to be - thus creating a perfect replica of "you". Now, since the original was destroyed in the process, one would be inclined to say that the person was transmitted. But was he?

Now let's consider the refined version. Here, the same information is collected, but the process is not destructive, the "original" is not affected. (Like our molecules are constantly vibrating with Browninan motion, but that does not affect us). Anyhow, the same information is gathered, transmitted, and the replica is assembled. The original may not even be aware of the whole process. In this case there can be no question that only a copy, or duplicate was created, since the original is still there.

In neither case can we speak of "transmitting" the person, in both instances we have a perfect copy process.

Now, let's consider one individual, in the different stages of life. The person is constantly changing, but "essentially" he is still the same person. (At the very least he did not change into a fish, or a rosebud, or an interstellar cloud.)

The question of "what" is "A" becomes a matter of definition. But no matter how we define the "A", it is "A" and not "B". As such the first law of logic applies.

[Devious]

Laws of logic are not laws, at all. Laws of logic are just an anthropomorphic expression we use to describe phenomenon in relatable language. Logic isnt prescriptive like laws in the way that we commonly use the term. Logic is descriptive. Logic is a tool in language we use for describing of all things that exist, consistently and reliably behave. When we call something a law of logic were talking about a precondition to existence. Thats it. It is a precondition of existence that something can be both X and not X at the same time in the same respect. It is a precondition of existence that something is itself. If it werent itself it would be something else. And that something else is itself, and if something is not itself, or something else it isnt.

Laws of logic arent for the universe. The universe doesnt need them. Theyre for us to understand the universe. Its not that that things that exist are following these rules or laws. Its that we have created rules and laws to follow things that exist These preconditions just are what they are. Existence just behaves the way it behaves.

[cnorman18]

The 'laws of logic' are descriptive.. They are conceptual, and therefore they are man made. Those who insist they are not are commit several logical fallacies. The first is the logical fallacy of equivocation by equating the 'laws with logic' with the facts of reality. That is sort of mixing up a map with the territory. Then there is the logical fallacy of reification, where the facts of reality are being treated as if they were independent entities. The 'laws of logic' do not govern reality, but rather describe how reality appears to work. The 'laws of logic' describe reality..it is merely a describe conceptual tool though.

VERY well said. After this post, one wonders why the debate continues. "Mixing up a map with the territory" -- I especially like that. "The word is not the thing." A common human error.

Anything expressed in words is not reality itself, but a human mental construct that we use to understand reality. The difference is not trivial; on the other hand, those mental constructs are all we have to think with. Trying to move beyond them is rather like trying to see without using one's eyes.