Is “Water is H2O” a posteriori necessary truth?

Richard B

Case #1

The concept of “water” can be shown by how we used this word in everyday life. Additionally, we quickly learn what this word refers to each time we use this word in such ways as “Can I have a drink of water”, or “I want to take a bath in a tub of water.” I also can come to learn the concept of “H2O” in the same way, such as “Can I have a drink of H2O?” or “I want to take a bath in a tub of H2O.” Experience teaches us the use of these words is the same, and thus, are the same concepts. “Water is H2O” simply means these are the same concepts. Is this true by definition? Yes, but I had to figure out if we were talking about the same concept on both sides of “is”. This was done by experiencing how these words were used in the stream of life. Could this turn out to be false, of course, our experience with these words could have shown that they were different concepts and referred to different things.

Case #2

The concept of “water” can be shown by how we used this word in everyday life. Additionally, we quickly learn what this word refers to each time we use this word in such ways as “Can I have a drink of water”, or “I want to take a bath in a tub of water.” However, the term “H2O” may take a some work to learn and use to satisfy the casual user, and may take a lot of effort to satisfy the expert. Much is needed to understand atomic theory, chemistry, physic, and math. Additionally, some understanding of scientific method, logic and experimental design may come in handy too. So, when the scientist takes a sample of that liquid and determine it to be “H2O”, this concept comes with much theory and learning. So when we say, now, that “Water is H2O” this can be false in one sense, and true in another sense. It is false in the sense that we are talking about completely different concepts that are learned in different ways and used is different ways. Alternatively, “Water = H20” might be true if I said, “Someone gave me this liquid and it looks like water. I ask the scientist, “Could you analyze this liquid and see if it is water.” He analyzes a sample and determines the liquid to be “H2O”. I say, “Oh, I thought it was water.” The scientist comes back and says “It is, ‘Water is H2O’. “

Case #3

A scientist has revealed that centuries of experimental data have been incorrect. And in fact, all of the water we have tested as “H2O” is incorrect. In fact, the actual chemical formula is “D2O”. So, “Water is H2O” turned out to be false. The correct statement should have been “Water is D2O”. Further centuries past, and another scientist comes out and declares “Water is not D2O”. In fact, we have come up with a more fundamental scientific theory regarding what the world is made of. This theory has greater predictive power and ties in nicely with our other theories. As a result of this theory, I declare “Water is C:\1234”

Calling “Water is H2O” a necessary a posteriori truth sounds truly odd given the three cases above. “Water is H2O” could not have been false, or is true in every possible world, and we know this by experience. OK, I will give you this, and what was I supposed to do with this knowledge, or should I say this metaphysics? Stop someone from denying that “Water is H2O” Stop a scientist from correcting his experimental results? Stop the scientist from coming up with new theories? Maybe Mr. Kripke would say that these were just necessary false propositions and this was known through experience. In any case, I would say that this metaphysical theory is insignificant based on my understanding how we use language in everyday life.

Post Script

In Naming and Necessity, Mr. Kripke says something interesting, “If there were a substance, even actually, which had a completely different atomic structure from that of water, but resembled water in these respects, would we say some water wasn’t H2O? I think not.”

I would say, yes, some language users might actually say this.

For example, I visit some distant world and I find a community living by two lakes. The community drinks, swims, and baths at both lakes. At each lake, they can be overheard saying such things as “I like to get a drink of water from that lake” or “Let’s take a swim in the water at this lake.” Being interested in this new world, I wondered about the make-up of this water. So I take some samples and test them. To my surprise, one lake is made up of “H2O” and the other is made up of “D2O” The communities found this information interesting, and said to me “Thank you very much, I guess some water was not “H2O” but “D2O”. I try to correct them by saying “Obviously you are not aware of Mr. Kripke’s metaphysics, you should be calling one “water”, and the other “fool’s water” or, better yet, “heavy water”. “Oh no”, they said, “Let us correct you! We do not find any practical differences between this water and that water; therefore, maybe Mr. Kripke should come up with a better metaphysics that actually describes how we use our language.”

Jonmel

Could you explain exactly the chemical make-up of D20?

jorndoe

My 2 ¢s.

H₂O is a model of water.
And such a successful one that we occasionally use the two interchangeably.
Even though the model is not the modeled.

Terrapin Station

Aside from the fact that nothing is a necessary truth, the answer is "No." Someone can use "water" to refer to XYZ, too, for example ("XYZ" being the "Twin Earth" substance that looks, tastes, etc. just like water, a la Putnam's "The Meaning of 'Meaning'").

It's not wrong to use "water" to refer to "XYZ," It's just unusual. It's not wrong to be unusual. Saying that common usage makes something right is the argumentum ad populum fallacy. And more bluntly, it's simply kowtowing to conformism.

To know how someone defines something, to know the definitional correlate to their concepts, you need to ask them, especially when they're clearly using a term or concept differently than you use it, different than what you're familiar with.

Richard B

Hilary Putnam says something interesting in “From The Meaning of Meaning” in which he says “In fact, once we have discovered the nature of water, nothing counts as a possible world in which water isn’t H2O.”

So this locks in the “necessity” of “water is H2O”? This seems to be a naive view of science and how it has been practiced. I think Thomas Kuhn said it best in “The Structure of Scientific Revolutions” when he said “Does it really help to imagine that there is some one full, objective, true account of nature and that the proper measure of scientific achievement is the extent to which it bring us closer to that ultimate goal? If we can learn to substitute evolution from-what-we-do-know for evolution-toward-what we-wish-to-know, a number of vexing problems may vanish in the process”

Wayfarer

As a matter of fact, there is a form of water which is D₂O, namely, 'heavy water - a form of water that contains a larger than normal amount of the hydrogen isotope deuterium rather than the common hydrogen-1 isotope that makes up most of the hydrogen in normal water. The presence of deuterium gives the water different nuclear properties, and the increase of mass gives it slightly different physical and chemical properties when compared to normal water'.

So you might have a world in which some or all the water is D₂O, which mitigates against Putnam, and also against water necessarily being H₂0

Wayfarer

Further to which, I would question whether ‘water’ is indeed a concept. I think, perhaps, liquidity is a concept, of which water is an example. So, a necessary fact about a liquid is that it is ‘something which flows and assumes the shape of any receptacle into which it is poured.’ But the fact that H₂O is a liquid, might actually be a contingent truth - contingent on, for example, the temperature at which it is stored.

Terrapin Station

↪Wayfarer

From the nominalist perspective, any universal/type term is a concept. No concepts are necessarily as they are.

Harry Hindu

My 2 ¢s.

H2O is a model of water.
And such a successful one that we occasionally use the two interchangeably.
Even though the model is not the modeled. — jorndoe

Or, to be more precise, H2O is a model of water at the molecular level. Water is a model at the macro level.

↪Richard B

in all of the replies in this thread there is still something that is the same in the world we are referring to. The term we use depends on the context, but we're still pointing to the same thing. We are still talking about the same thing. You refer to your mom as "Mom", but others may refer to her with her proper name. Does that mean she is two seperate people?

Wayfarer

No concepts are necessarily as they are. — Terrapin Station

:confused:

Terrapin Station

↪Wayfarer

Not sure what the question or comment is there. :wink:

Richard B

1. I agree with your “Mom” example in this respect: If I point to a glass of liquid and say “water”, “H2O”, “agua”, I may be showing I understand these names and I am referring to that object.

2. However, the use of “H20” in a scientific context is not learned by pointing to an object, and not used by pointing to objects. The term requires a great deal of understanding of scientific theory. Like any scientific theory, it can be shown to be false, incomplete, useless, etc...

3. The object I point to is called “Mom”. That is a “Macro” model. I provide a complete genetic or atomic description of “Mom”. That is a “Molecular” level. Lets say this object changes in some minor way at the molecular level. Is this the same “Mom” or the same person anymore? What if “Mom” lost an arm at the macro level and I did not call her “Mom” anymore? Am I incorrect? Does reference really matter here as long as there is no misunderstanding in any particular case?

frank

↪Richard B

Kripke's point depends on the understanding that H20=water is an identity statement. They're both rigid designators picking out the same object in all possible worlds.

You're free to imagine alternative uses of the words so that they don't pick out the same object, but that would be to miss Kripke's point, not refute it.

Richard B

Kripke, N&N says the following “I have the table in my hands I can point to it, and when I ask whether it might have been in another room, I am talking, by definition, about it. I don't have to identify it after seeing it through a telescope.”

It is unclear to me if “picking out” something in a possible world is the same as “stipulating by definition” what one is talking about. But definitely I think we are in the realm of concepts and I do not want to dispute Kripke’s metaphysics. However, what I am disputing is if his theory is of any significance. Specifically, I want to judge this theory in terms of applicability to the way we use language and its use in the world we live in. Here I find it lacking.

Again what am I suppose to do with the notion that “water is H20” is a necessary posteriori truth? Lets say we keep learning the scientist got it wrong with the elements “water is CO” one time, “water is LO” another time, etc. What does Kripke say “ No matter what you say you were always referring and will always be referring to the same thing.”

And what was that Mr Kripke? I am not sure anymore, can I have a description now?

frank

Again what am I suppose to do with the notion that “water is H20” is a necessary a posteriori truth? — Richard B

Place it in the context of the history of analytic philosophy.

Terrapin Station

However, the use of “H20” in a scientific context is not learned by pointing to an object, and not used by pointing to objects. — Richard B

This seems very wonky to me, but maybe you mean something more limited by "pointing to an object" than I would mean?

Terrapin Station

Kripke's point depends on the understanding that H20=water is an identity statement. They're both rigid designators picking out the same object in all possible worlds. — frank

I forgot how that's supposed to work a la Kripke. It seems to me that "H2O" would normally turn out to be something like "the first chancellor of the German Empire" re "Bismarck," so that if what we had christened "water" hadn't been H2O (or wouldn't be H2O in some possible world), most people wouldn't say, "Oh, we can't call that 'water.'"

Richard B

The other issue I have with Kripke is the following:

In Naming and Necessity, Mr. Kripke says something interesting, “If there were a substance, even actually, which had a completely different atomic structure from that of water, but resembled water in these respects, would we say some water wasn’t H2O? I think not.”

Again, is Kripke attempting to say how we should use our language because it does not agree with his metaphysics? Again, we certainly can imagine a world where a group of language users do indeed say such a thing (see my first post).

Wittgenstein gave up looking for the underlying logic of our language and looked at how we use it. Not sure what Kripke’s intent is, but I will give him his narrow application to history of analytical philosophy. Just don't think that “necessary” means much in a larger context.

frank

It seems to me that "H2O" would normally turn out to be something like "the first chancellor of the German Empire" re "Bismarck," — Terrapin Station

I don't think "the first chancellor of the German Empire" is a rigid designator.

frank

but I will give him his narrow application to history of analytical philosophy. — Richard B

Cool.

Sculptor

H2O is a model of water which is not immediately a posteriori.
But just about anyone can put an anode and a cathode into water and collect gas. You will find that the two gases bubbling from the water is in the proportion of 2:1. Put one gas in a balloon and it will rise, put the other in a balloon and it will sink.
A posteriori you can say that water is constituted by two gases which conform to expected proportions and qualities. Both gases are inflammable, as predicted, and their weights can be also determined as expected.
So you have moved from an a priori assertion to an a posteriori conformation.
In itself, "H2O" could refer to anything. Demonstrations offer models.

Terrapin Station

I don't think "the first chancellor of the German Empire" is a rigid designator. — frank

Right--that was my point. It seems to me that it should be a contingent property of water, where the chemical make-up would be potentially different in possible worlds.

frank

Right--that was my point. It seems to me that it should be a contingent property of water, where the chemical make-up would be potentially different in possible worlds. — Terrapin Station

Then his point isn't striking you as intuitive. He was banking on the likelihood that it would strike you so. Or it might just be that example.

How about Hesperus and Phosphorus? Does that one work for you?

Terrapin Station

↪frank

It doesn't work as a necessary identity (if that's what he was arguing--I don't recall). The only way rigid designators work for me in general is in the guise of someone christening something by a proper name (or treating something as a proper name), where the christener would still use that proper name even if the facts about the person/thing/etc. in question were different. I don't see how that works for identities, though (and I can't recall why Kripke would have thought it would work), unless it's something maybe where the identity was known upon the christening, so that the identity more or less functions as a proper name as a whole to the christener.

Richard B

Let me try another way to show the claim that “water is H2O” is a posteriori necessary truth is problematic. First, it seems to me, that if we learn to point to the glass if liquid and call it “water” one time and call it “H2O” another time, it is using the word the same same way to refer to the same thing. No problems here. The words mean the same so by definition it is necessary. Whether a prior or a posteriori, you pick.

We also learn the word “H2O” another away. And to learn how to use it appropriately within the scientific community may take a lot education. Such things as atomic theory, elemental analysis, particle physics to name a few. To learn this concept is not done by pointing to a glass of water, though some do per the first example. In first example, I am referring to the glass of liquid, in the second example I am not referring to the liquid, if anything I am tentatively referring to an elemental formula. The next step to establish the identity of the liquid is by conducting an experiment to determine the elemental formula. The scientist comes back with “H2O”. This was established by experience, a posteriori. However, this could have been wrong, the experiment was performed incorrectly or worse our scientific theory incomplete. This is contingent. How can the term which can potentially be revised to refer to other elements establish an identity as necessary in this particular case? If you say to me, it does not matter you were always referring to the same thing anyway, I would say maybe you are confusing the first example with the second.

Terrapin Station

The words mean the same so by definition it is necessary. — Richard B

That doesn't seem to be using "necessary" in the right way. The definition could be different than it is. The chemical composition could have turned out to be different, too. (So in this regard, it's agreeing with you that "water is H2O is problematic as something necessary a posteriori)

Re the other part, yeah, that's not done by pointing to a glass of water primarily, but isn't it done by pointing to other things?

Richard B

Going back to Putnam’s support of Kripke from “The Meaning of Meaning” in which he says “In fact, once we have discovered the nature of water, nothing counts as a possible world in which water isn’t H2O.”

Waiting for the final determination on “Nature of water” never comes in science, only the next series of experiences that could undermine our theory lies in the wake. And this is the foundation in which Kripke “necessary” rest upon. This does not seem necessary at all.

Terrapin Station

↪Richard B

If only I agreed with Putnam. :wink:

Richard B

To further clarify may concern of such identity statements as “water is H2O”and saying “if such an identity statement is true, it is true in all possible worlds - a necessity” is as follows:

Could we ever arrive that this kind of identity statement is true since it will aways be open to refutation from some future experience? If this is the case, then it could never be a necessity. This is a fact based on our experiences and history of science.

Rich

Wayfarer

↪Richard B

I don’t think your depicting ‘necessary truth’ correctly. I would always categorise such facts as chemical formula as contingent rather than necessary.

once we have discovered the nature of water, nothing counts as a possible world in which water isn’t H2O.” — Richard B

As I already noted, and you seem to have ignored, there is such as thing as heavy water, D₂0, which is another form of water.

Harry Hindu

However, the use of “H20” in a scientific context is not learned by pointing to an object, and not used by pointing to objects. The term requires a great deal of understanding of scientific theory. Like any scientific theory, it can be shown to be false, incomplete, useless, etc... — Richard B

If you arent referring to something in the world when you use the term, "H2O", then what would you be talking about? Would you be referring to a molecule or a scientific theory, both of which are in the world, no?

The object I point to is called “Mom”. That is a “Macro” model. I provide a complete genetic or atomic description of “Mom”. That is a “Molecular” level. Lets say this object changes in some minor way at the molecular level. Is this the same “Mom” or the same person anymore? What if “Mom” lost an arm at the macro level and I did not call her “Mom” anymore? Am I incorrect? Does reference really matter here as long as there is no misunderstanding in any particular case? — Richard B

H2O would be the smallest one could go and still be referring to water - a molecule. At the atomic level of hydrogen and oxygen you no longer have water.

Your mom is to complex to be defined by the behavior of a single atom, molecule, or organ. She would be all of these working together as a whole. Once you reach the size scale of organisms and their behaviors you reach what it is to be your mom. Your mom is a particular arrangement of organs that work together. Beyond that youd be referring to the environment. Is your mom an organism or an environment? Is the building your mom is in your mom, or just a particular organism inside the building?

As for your mom losing an arm, I would say that she is still your mom as part of what it is to be an organism is the understanding that they can change to degree and still be the same thing. How much of a change before your mom becomes something else entirely? I guess that is dependent upon how we define an organism. Organisms are born as an entity and are that same entity until they die. Everything in between is just change that the organism undergoes in its lifetime.

Is “Water is H2O” a posteriori necessary truth?

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